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1.
Physiol Plant ; 176(3): e14374, 2024.
Article in English | MEDLINE | ID: mdl-38837422

ABSTRACT

Heat stress substantially reduces tomato (Solanum lycopersicum) growth and yield globally, thereby jeopardizing food security. DnaJ proteins, constituents of the heat shock protein system, protect cells from diverse environmental stresses as HSP-70 molecular co-chaperones. In this study, we demonstrated that AdDjSKI, a serine-rich DnaJ III protein induced by pathogens, plays an important role in stabilizing photosystem II (PSII) in response to heat stress. Our results revealed that transplastomic tomato plants expressing the AdDjSKI gene exhibited increased levels of total soluble proteins, improved growth and chlorophyll content, reduced malondialdehyde (MDA) accumulation, and diminished PSII photoinhibition under elevated temperatures when compared with wild-type (WT) plants. Intriguingly, these transplastomic plants maintained higher levels of D1 protein under elevated temperatures compared with the WT plants, suggesting that overexpression of AdDjSKI in plastids is crucial for PSII protection, likely due to its chaperone activity. Furthermore, the transplastomic plants displayed lower accumulation of superoxide radical (O2 •─) and H2O2, in comparison with the WT plants, plausibly attributed to higher superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities. This also coincides with an enhanced expression of corresponding genes, including SlCuZnSOD, SlFeSOD, SlAPX2, and SltAPX, under heat stress. Taken together, our findings reveal that chloroplastic expression of AdDjSKI in tomatoes plays a critical role in fruit yield, primarily through a combination of delayed senescence and stabilizing PSII under heat stress.


Subject(s)
Fruit , Heat-Shock Response , Photosystem II Protein Complex , Plant Leaves , Plant Proteins , Plastids , Solanum lycopersicum , Solanum lycopersicum/genetics , Solanum lycopersicum/physiology , Solanum lycopersicum/growth & development , Solanum lycopersicum/metabolism , Photosystem II Protein Complex/metabolism , Photosystem II Protein Complex/genetics , Heat-Shock Response/genetics , Fruit/genetics , Fruit/growth & development , Fruit/physiology , Fruit/metabolism , Plant Proteins/metabolism , Plant Proteins/genetics , Plant Leaves/genetics , Plant Leaves/physiology , Plant Leaves/metabolism , Plastids/metabolism , Plastids/genetics , Chlorophyll/metabolism , HSP40 Heat-Shock Proteins/metabolism , HSP40 Heat-Shock Proteins/genetics , Plants, Genetically Modified , Plant Senescence/genetics , Gene Expression Regulation, Plant , Malondialdehyde/metabolism
2.
Proc Natl Acad Sci U S A ; 121(24): e2320064121, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38833477

ABSTRACT

Synapse maintenance is essential for generating functional circuitry, and decrement in this process is a hallmark of neurodegenerative disease. Yet, little is known about synapse maintenance in vivo. Cysteine string protein α (CSPα), encoded by the Dnajc5 gene, is a synaptic vesicle chaperone that is necessary for synapse maintenance and linked to neurodegeneration. To investigate the transcriptional changes associated with synapse maintenance, we performed single-nucleus transcriptomics on the cortex of young CSPα knockout (KO) mice and littermate controls. Through differential expression and gene ontology analysis, we observed that both neurons and glial cells exhibit unique signatures in the CSPα KO brain. Significantly, all neuronal classes in CSPα KO brains show strong signatures of repression in synaptic pathways, while up-regulating autophagy-related genes. Through visualization of synapses and autophagosomes by electron microscopy, we confirmed these alterations especially in inhibitory synapses. Glial responses varied by cell type, with microglia exhibiting activation. By imputing cell-cell interactions, we found that neuron-glia interactions were specifically increased in CSPα KO mice. This was mediated by synaptogenic adhesion molecules, with the classical Neurexin1-Neuroligin 1 pair being the most prominent, suggesting that communication of glial cells with neurons is strengthened in CSPα KO mice to preserve synapse maintenance. Together, this study provides a rich dataset of transcriptional changes in the CSPα KO cortex and reveals insights into synapse maintenance and neurodegeneration.


Subject(s)
HSP40 Heat-Shock Proteins , Membrane Proteins , Mice, Knockout , Neurons , Synapses , Transcriptome , Animals , Synapses/metabolism , Mice , HSP40 Heat-Shock Proteins/genetics , HSP40 Heat-Shock Proteins/metabolism , Neurons/metabolism , Membrane Proteins/metabolism , Membrane Proteins/genetics , Neuroglia/metabolism
3.
Theor Appl Genet ; 137(7): 149, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38836874

ABSTRACT

KEY MESSAGE: Analyze the evolutionary pattern of DNAJ protein genes in the Panicoideae, including pearl millet, to identify and characterize the biological function of PgDNAJ genes in pearl millet. Global warming has become a major factor threatening food security and human development. It is urgent to analyze the heat-tolerant mechanism of plants and cultivate crops that are adapted to high temperature conditions. The Panicoideae are the second largest subfamily of the Poaceae, widely distributed in warm temperate and tropical regions. Many of these species have been reported to have strong adaptability to high temperature stress, such as pearl millet, foxtail millet and sorghum. The evolutionary differences in DNAJ protein genes among 12 Panicoideae species and 10 other species were identified and analyzed. Among them, 79% of Panicoideae DNAJ protein genes were associated with retrotransposon insertion. Analysis of the DNAJ protein pan-gene family in six pearl millet accessions revealed that the non-core genes contained significantly more TEs than the core genes. By identifying and analyzing the distribution and types of TEs near the DNAJ protein genes, it was found that the insertion of Copia and Gypsy retrotransposons provided the source of expansion for the DNAJ protein genes in the Panicoideae. Based on the analysis of the evolutionary pattern of DNAJ protein genes in Panicoideae, the PgDNAJ was obtained from pearl millet through identification. PgDNAJ reduces the accumulation of reactive oxygen species caused by high temperature by activating ascorbate peroxidase (APX), thereby improving the heat resistance of plants. In summary, these data provide new ideas for mining potential heat-tolerant genes in Panicoideae, and help to improve the heat tolerance of other crops.


Subject(s)
Pennisetum , Plant Proteins , Pennisetum/genetics , Pennisetum/physiology , Plant Proteins/genetics , Plant Proteins/metabolism , Phylogeny , HSP40 Heat-Shock Proteins/genetics , Gene Expression Regulation, Plant , Retroelements/genetics , Poaceae/genetics , Evolution, Molecular , Genes, Plant
4.
Stem Cell Res ; 77: 103427, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38696852

ABSTRACT

The DNAJC19 gene, a member of DNAJ heat shock protein (Hsp40) family, is localized within the inner mitochondrial membrane (IMM) and plays a crucial role in regulating the function and localization of mitochondrial Hsp70 (MtHsp70). Mutations in the DNAJC19 gene cause Dilated Cardiomyopathy with Ataxia Syndrome (DCMA). The precise mechanisms underlying the DCMA phenotype caused by DNAJC19 mutations remain poorly understood, and effective treatment modalities were lacking unitl recently. By using CRISPR-Cas9 gene editing technology, this study generated a DNAJC19-knockout (DNAJC19-KO) human embryonic stem cell line (hESC), which will be a useful tool in studying the pathogenesis of DCMA.


Subject(s)
CRISPR-Cas Systems , HSP40 Heat-Shock Proteins , Human Embryonic Stem Cells , Humans , Human Embryonic Stem Cells/metabolism , Human Embryonic Stem Cells/cytology , HSP40 Heat-Shock Proteins/genetics , HSP40 Heat-Shock Proteins/metabolism , Gene Knockout Techniques , Cell Line , Homozygote
5.
FASEB J ; 38(9): e23630, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38713100

ABSTRACT

Heat shock proteins (HSPs) are a group of highly conserved proteins found in a wide range of organisms. In recent years, members of the HSP family were overexpressed in various tumors and widely involved in oncogenesis, tumor development, and therapeutic resistance. In our previous study, DNAJC24, a member of the DNAJ/HSP40 family of HSPs, was found to be closely associated with the malignant phenotype of hepatocellular carcinoma. However, its relationship with other malignancies needs to be further explored. Herein, we demonstrated that DNAJC24 exhibited upregulated expression in LUAD tissue samples and predicted poor survival in LUAD patients. The upregulation of DNAJC24 expression promoted proliferation and invasion of LUAD cells in A549 and NCI-H1299 cell lines. Further studies revealed that DNAJC24 could regulate the PI3K/AKT signaling pathway by affecting AKT phosphorylation. In addition, a series of experiments such as Co-IP and mass spectrometry confirmed that DNAJC24 could directly interact with PCNA and promoted the malignant phenotypic transformation of LUAD. In conclusion, our results suggested that DNAJC24 played an important role in the progression of LUAD and may serve as a specific prognostic biomarker for LUAD patients. The DNAJC24/PCNA/AKT axis may be a potential target for future individualized and precise treatment of LUAD patients.


Subject(s)
Cell Proliferation , HSP40 Heat-Shock Proteins , Proliferating Cell Nuclear Antigen , Proto-Oncogene Proteins c-akt , Animals , Female , Humans , Male , Mice , Middle Aged , Cell Line, Tumor , Disease Progression , Gene Expression Regulation, Neoplastic , HSP40 Heat-Shock Proteins/metabolism , HSP40 Heat-Shock Proteins/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Lung Neoplasms/genetics , Mice, Inbred BALB C , Mice, Nude , Phosphorylation , Proliferating Cell Nuclear Antigen/metabolism , Proliferating Cell Nuclear Antigen/genetics , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-akt/genetics , Signal Transduction
6.
Nat Commun ; 15(1): 3285, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38627370

ABSTRACT

DNAJB6b is a molecular chaperone of the heat shock protein network, shown to play a crucial role in preventing aggregation of several disease-related intrinsically disordered proteins. Using homology modeling and microsecond-long all-atom molecular dynamics (MD) simulations, we show that monomeric DNAJB6b is a transiently interconverting protein cycling between three states: a closed state, an open state (both abundant), and a less abundant extended state. Interestingly, the reported regulatory autoinhibitory anchor between helix V in the G/F1 region and helices II/III of the J-domain, which obstructs the access of Hsp70 to the J-domain remains present in all three states. This possibly suggests a mechanistically intriguing regulation in which DNAJB6b only becomes exposed when loaded with substrates that require Hsp70 processing. Our MD results of DNAJB6b carrying mutations in the G/F1 region that are linked to limb-girdle muscular dystrophy type D1 (LGMDD1) show that this G/F1 region becomes highly dynamic, pointing towards a spontaneous release of the autoinhibitory helix V from helices II/III. This would increase the probability of non-functional Hsp70 interactions to DNAJB6b without substrates. Our cellular data indeed confirm that non-substrate loaded LGMDD1 mutants have aberrant interactions with Hsp70.


Subject(s)
Molecular Chaperones , Muscular Dystrophies, Limb-Girdle , Humans , Molecular Chaperones/metabolism , HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Proteins/metabolism , Molecular Dynamics Simulation , Molecular Conformation , HSP40 Heat-Shock Proteins/metabolism
7.
PLoS Biol ; 22(4): e3002585, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38648719

ABSTRACT

Orb2 the Drosophila homolog of cytoplasmic polyadenylation element binding (CPEB) protein forms prion-like oligomers. These oligomers consist of Orb2A and Orb2B isoforms and their formation is dependent on the oligomerization of the Orb2A isoform. Drosophila with a mutation diminishing Orb2A's prion-like oligomerization forms long-term memory but fails to maintain it over time. Since this prion-like oligomerization of Orb2A plays a crucial role in the maintenance of memory, here, we aim to find what regulates this oligomerization. In an immunoprecipitation-based screen, we identify interactors of Orb2A in the Hsp40 and Hsp70 families of proteins. Among these, we find an Hsp40 family protein Mrj as a regulator of the conversion of Orb2A to its prion-like form. Mrj interacts with Hsp70 proteins and acts as a chaperone by interfering with the aggregation of pathogenic Huntingtin. Unlike its mammalian homolog, we find Drosophila Mrj is neither an essential gene nor causes any gross neurodevelopmental defect. We observe a loss of Mrj results in a reduction in Orb2 oligomers. Further, Mrj knockout exhibits a deficit in long-term memory and our observations suggest Mrj is needed in mushroom body neurons for the regulation of long-term memory. Our work implicates a chaperone Mrj in mechanisms of memory regulation through controlling the oligomerization of Orb2A and its association with the translating ribosomes.


Subject(s)
Drosophila Proteins , HSP40 Heat-Shock Proteins , Memory, Long-Term , Animals , Drosophila melanogaster/metabolism , Drosophila melanogaster/genetics , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , HSP40 Heat-Shock Proteins/metabolism , HSP40 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/metabolism , HSP70 Heat-Shock Proteins/genetics , Memory, Long-Term/physiology , mRNA Cleavage and Polyadenylation Factors/metabolism , mRNA Cleavage and Polyadenylation Factors/genetics , Mushroom Bodies/metabolism , Protein Multimerization , Transcription Factors/metabolism , Transcription Factors/genetics , Molecular Chaperones/genetics , Molecular Chaperones/metabolism
8.
ACS Chem Neurosci ; 15(9): 1732-1737, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38640082

ABSTRACT

For many chaperones, a propensity to self-assemble correlates with function. The highly efficient amyloid suppressing chaperone DNAJB6b has been reported to oligomerize. A key question is whether the DNAJB6b self-assemblies or their subunits are active units in the suppression of amyloid formation. Here, we address this question using a nonmodified chaperone. We use the well-established aggregation kinetics of the amyloid ß 42 peptide (Aß42) as a readout of the amyloid suppression efficiency. The experimental setup relies on the slow dissociation of DNAJB6b assemblies upon dilution. We find that the dissociation of the chaperone assemblies correlates with its ability to suppress fibril formation. Thus, the data show that the subunits of DNAJB6b assemblies rather than the large oligomers are the active forms in amyloid suppression. Our results provide insights into how DNAJB6b operates as a chaperone and illustrate the importance of established assembly equilibria and dissociation rates for the design of kinetic experiments.


Subject(s)
Amyloid beta-Peptides , HSP40 Heat-Shock Proteins , Molecular Chaperones , HSP40 Heat-Shock Proteins/metabolism , Humans , Molecular Chaperones/metabolism , Amyloid beta-Peptides/metabolism , Nerve Tissue Proteins/metabolism , Amyloid/metabolism , Peptide Fragments/metabolism , Kinetics
9.
EMBO J ; 43(11): 2166-2197, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38600242

ABSTRACT

The centromeric histone H3 variant CENP-A is overexpressed in many cancers. The mislocalization of CENP-A to noncentromeric regions contributes to chromosomal instability (CIN), a hallmark of cancer. However, pathways that promote or prevent CENP-A mislocalization remain poorly defined. Here, we performed a genome-wide RNAi screen for regulators of CENP-A localization which identified DNAJC9, a J-domain protein implicated in histone H3-H4 protein folding, as a factor restricting CENP-A mislocalization. Cells lacking DNAJC9 exhibit mislocalization of CENP-A throughout the genome, and CIN phenotypes. Global interactome analysis showed that DNAJC9 depletion promotes the interaction of CENP-A with the DNA-replication-associated histone chaperone MCM2. CENP-A mislocalization upon DNAJC9 depletion was dependent on MCM2, defining MCM2 as a driver of CENP-A deposition at ectopic sites when H3-H4 supply chains are disrupted. Cells depleted for histone H3.3, also exhibit CENP-A mislocalization. In summary, we have defined novel factors that prevent mislocalization of CENP-A, and demonstrated that the integrity of H3-H4 supply chains regulated by histone chaperones such as DNAJC9 restrict CENP-A mislocalization and CIN.


Subject(s)
Centromere Protein A , Chromosomal Instability , Histones , Humans , Centromere Protein A/metabolism , Centromere Protein A/genetics , Histones/metabolism , Histones/genetics , Minichromosome Maintenance Complex Component 2/metabolism , Minichromosome Maintenance Complex Component 2/genetics , HeLa Cells , HSP40 Heat-Shock Proteins/metabolism , HSP40 Heat-Shock Proteins/genetics , Chromosomal Proteins, Non-Histone/metabolism , Chromosomal Proteins, Non-Histone/genetics , Centromere/metabolism
10.
Cardiovasc Diabetol ; 23(1): 126, 2024 Apr 13.
Article in English | MEDLINE | ID: mdl-38614964

ABSTRACT

BACKGROUND: The accumulation of visceral and ectopic fat comprise a major cause of cardiometabolic diseases. However, novel drug targets for reducing unnecessary visceral and ectopic fat are still limited. Our study aims to provide a comprehensive investigation of the causal effects of the plasma proteome on visceral and ectopic fat using Mendelian randomization (MR) approach. METHODS: We performed two-sample MR analyses based on five large genome-wide association study (GWAS) summary statistics of 2656 plasma proteins, to screen for causal associations of these proteins with traits of visceral and ectopic fat in over 30,000 participants of European ancestry, as well as to assess mediation effects by risk factors of outcomes. The colocalization analysis was conducted to examine whether the identified proteins and outcomes shared casual variants. RESULTS: Genetically predicted levels of 14 circulating proteins were associated with visceral and ectopic fat (P < 4.99 × 10- 5, at a Bonferroni-corrected threshold). Colocalization analysis prioritized ten protein targets that showed effect on outcomes, including FST, SIRT2, DNAJB9, IL6R, CTSA, RGMB, PNLIPRP1, FLT4, PPY and IL6ST. MR analyses revealed seven risk factors for visceral and ectopic fat (P < 0.0024). Furthermore, the associations of CTSA, DNAJB9 and IGFBP1 with primary outcomes were mediated by HDL-C and SHBG. Sensitivity analyses showed little evidence of pleiotropy. CONCLUSIONS: Our study identified candidate proteins showing putative causal effects as potential therapeutic targets for visceral and ectopic fat accumulation and outlined causal pathways for further prevention of downstream cardiometabolic diseases.


Subject(s)
Adiposity , Cardiovascular Diseases , Humans , Adiposity/genetics , Proteome , Genome-Wide Association Study , Mendelian Randomization Analysis , Obesity , Membrane Proteins , Molecular Chaperones , HSP40 Heat-Shock Proteins
11.
Mol Med Rep ; 29(5)2024 05.
Article in English | MEDLINE | ID: mdl-38551163

ABSTRACT

Endothelial barrier disruption plays a key role in the pathophysiology of heat stroke (HS). Knockout of DNAJA1 (DNAJA1­KO) is thought to be protective against HS based on a genome­wide CRISPR­Cas9 screen experiment. The present study aimed to illustrate the function of DNAJA1­KO against HS in human umbilical vein endothelial cells. DNAJA1­KO cells were infected using a lentivirus to investigate the role of DNAJA1­KO in HS­induced endothelial barrier disruption. It was shown that DNAJA1­KO could ameliorate decreased cell viability and increased cell injury, according to the results of Cell Counting Kit­8 and lactate dehydrogenase assays. Moreover, HS­induced endothelial cell apoptosis was inhibited by DNAJA1­KO, as indicated by Annexin V­FITC/PI staining and cleaved­caspase­3 expression using flow cytometry and western blotting, respectively. Furthermore, the endothelial barrier function, as measured by transepithelial electrical resistance and FITC­Dextran, was sustained during HS. DNAJA1­KO was not found to have a significant effect on the expression and distribution of cell junction proteins under normal conditions without HS. However, DNAJA1­KO could effectively protect the HS­induced decrease in the expression and distribution of cell junction proteins, including zonula occludens­1, claudin­5, junctional adhesion molecule A and occludin. A total of 4,394 proteins were identified using proteomic analysis, of which 102 differentially expressed proteins (DEPs) were activated in HS­induced wild­type cells and inhibited by DNAJA1­KO. DEPs were investigated by enrichment analysis, which demonstrated significant enrichment in the 'calcium signaling pathway' and associations with vascular­barrier regulation. Furthermore, the 'myosin light­chain kinase (MLCK)­MLC signaling pathway' was proven to be activated by HS and inhibited by DNAJA1­KO, as expected. Moreover, DNAJA1­KO mice and a HS mouse model were established to demonstrate the protective effects on endothelial barrier in vivo. In conclusion, the results of the present study suggested that DNAJA1­KO alleviates HS­induced endothelial barrier disruption by improving thermal tolerance and suppressing the MLCK­MLC signaling pathway.


Subject(s)
HSP40 Heat-Shock Proteins , Heat Stroke , Animals , Humans , Mice , Heat Stroke/genetics , Heat Stroke/metabolism , HSP40 Heat-Shock Proteins/genetics , Human Umbilical Vein Endothelial Cells , Mice, Knockout , Proteomics , Signal Transduction
12.
BMC Neurol ; 24(1): 96, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38491364

ABSTRACT

BACKGROUND: The Limb Girdle Muscular Dystrophies (LGMDs) are characterized by progressive weakness of the shoulder and hip girdle muscles as a result of over 30 different genetic mutations. This study is designed to develop clinical outcome assessments across the group of disorders. METHODS/DESIGN: The primary goal of this study is to evaluate the utility of a set of outcome measures on a wide range of LGMD phenotypes and ability levels to determine if it would be possible to use similar outcomes between individuals with different phenotypes. We will perform a multi-center, 12-month study of 188 LGMD patients within the established Genetic Resolution and Assessments Solving Phenotypes in LGMD (GRASP-LGMD) Research Consortium, which is comprised of 11 sites in the United States and 2 sites in Europe. Enrolled patients will be clinically affected and have mutations in CAPN3 (LGMDR1), ANO5 (LGMDR12), DYSF (LGMDR2), DNAJB6 (LGMDD1), SGCA (LGMDR3), SGCB (LGMDR4), SGCD (LGMDR6), or SGCG (LGMDR5, or FKRP-related (LGMDR9). DISCUSSION: To the best of our knowledge, this will be the largest consortium organized to prospectively validate clinical outcome assessments (COAs) in LGMD at its completion. These assessments will help clinical trial readiness by identifying reliable, valid, and responsive outcome measures as well as providing data driven clinical trial decision making for future clinical trials on therapeutic agents for LGMD. The results of this study will permit more efficient clinical trial design. All relevant data will be made available for investigators or companies involved in LGMD therapeutic development upon conclusion of this study as applicable. TRIAL REGISTRATION: Clinicaltrials.gov NCT03981289; Date of registration: 6/10/2019.


Subject(s)
Muscular Dystrophies, Limb-Girdle , Sarcoglycanopathies , Humans , Muscular Dystrophies, Limb-Girdle/diagnosis , Muscular Dystrophies, Limb-Girdle/genetics , Phenotype , Muscle, Skeletal , Mutation/genetics , Nerve Tissue Proteins/genetics , Molecular Chaperones/genetics , HSP40 Heat-Shock Proteins/genetics , Pentosyltransferases/genetics , Anoctamins/genetics
13.
PLoS Genet ; 20(3): e1011216, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38512964

ABSTRACT

Fibrolamellar carcinoma (FLC) is a rare liver cancer that disproportionately affects adolescents and young adults. Currently, no standard of care is available and there remains a dire need for new therapeutics. Most patients harbor the fusion oncogene DNAJB1-PRKACA (DP fusion), but clinical inhibitors are not yet developed and it is critical to identify downstream mediators of FLC pathogenesis. Here, we identify long noncoding RNA LINC00473 among the most highly upregulated genes in FLC tumors and determine that it is strongly suppressed by RNAi-mediated inhibition of the DP fusion in FLC tumor epithelial cells. We show by loss- and gain-of-function studies that LINC00473 suppresses apoptosis, increases the expression of FLC marker genes, and promotes FLC growth in cell-based and in vivo disease models. Mechanistically, LINC00473 plays an important role in promoting glycolysis and altering mitochondrial activity. Specifically, LINC00473 knockdown leads to increased spare respiratory capacity, which indicates mitochondrial fitness. Overall, we propose that LINC00473 could be a viable target for this devastating disease.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , RNA, Long Noncoding , Adolescent , Humans , Young Adult , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Cyclic AMP-Dependent Protein Kinase Catalytic Subunits/genetics , HSP40 Heat-Shock Proteins/genetics , HSP40 Heat-Shock Proteins/metabolism , Liver Neoplasms/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism
14.
Cell Stress Chaperones ; 29(2): 338-348, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38521349

ABSTRACT

The 70 kDa heat shock protein (Hsp70) chaperones control protein homeostasis in all ATP-containing cellular compartments. J-domain proteins (JDPs) coevolved with Hsp70s to trigger ATP hydrolysis and catalytically upload various substrate polypeptides in need to be structurally modified by the chaperone. Here, we measured the protein disaggregation and refolding activities of the main yeast cytosolic Hsp70, Ssa1, in the presence of its most abundant JDPs, Sis1 and Ydj1, and two swap mutants, in which the J-domains have been interchanged. The observed differences by which the four constructs differently cooperate with Ssa1 and cooperate with each other, as well as their observed intrinsic ability to bind misfolded substrates and trigger Ssa1's ATPase, indicate the presence of yet uncharacterized intramolecular dynamic interactions between the J-domains and the remaining C-terminal segments of these proteins. Taken together, the data suggest an autoregulatory role to these intramolecular interactions within both type A and B JDPs, which might have evolved to reduce energy-costly ATPase cycles by the Ssa1-4 chaperones that are the most abundant Hsp70s in the yeast cytosol.


Subject(s)
Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolism , HSP40 Heat-Shock Proteins/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Protein Binding , HSP70 Heat-Shock Proteins/metabolism , Molecular Chaperones/metabolism , Adenosine Triphosphatases/metabolism , Adenosine Triphosphate/metabolism
15.
Medicine (Baltimore) ; 103(13): e37555, 2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38552055

ABSTRACT

Endometrioid endometrial cancer (EEC) is one of the most common gynecologic malignancies. The interaction between cancer cells and the cells in the tumor microenvironment (TME) plays a crucial role in determining disease progression and response to treatment. To better understand the diversity in the TME of ECC, we conducted a comprehensive analysis using single-cell RNA sequencing across 21 samples, including 16 ECC and 5 adjacent normal tissues. We primarily focused on tumor-infiltrating natural killer (NK) cells and their cell-cell interactions with other immune cell types. We identified a CD56dim_DNAJB1 NK cells subset, which had low cytotoxic capability and high stress levels, suggesting a dysfunctional state. This subset showed strong interactions with tumor-associated macrophages through several ligand-receptor pairs. Additionally, we observed that tumor-infiltrating LAMP3+ dendritic cells may inhibit CD8+ T cells or attract regulatory T cells to the tumor area. These dendritic cells also had impaired activation effects on NK cells within the TME. Our study provides valuable insights into the role of NK cells in cancer immunity and highlights the potential of targeting specific NK cell subsets for therapeutic purposes.


Subject(s)
Antineoplastic Agents , Carcinoma, Endometrioid , Female , Humans , Carcinoma, Endometrioid/genetics , Killer Cells, Natural , CD8-Positive T-Lymphocytes , Gene Expression Profiling , Tumor Microenvironment , HSP40 Heat-Shock Proteins
16.
Cell Rep Med ; 5(3): 101469, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38508137

ABSTRACT

Fibrolamellar carcinoma (FLC) is a liver tumor with a high mortality burden and few treatment options. A promising therapeutic vulnerability in FLC is its driver mutation, a conserved DNAJB1-PRKACA gene fusion that could be an ideal target neoantigen for immunotherapy. In this study, we aim to define endogenous CD8 T cell responses to this fusion in FLC patients and evaluate fusion-specific T cell receptors (TCRs) for use in cellular immunotherapies. We observe that fusion-specific CD8 T cells are rare and that FLC patient TCR repertoires lack large clusters of related TCR sequences characteristic of potent antigen-specific responses, potentially explaining why endogenous immune responses are insufficient to clear FLC tumors. Nevertheless, we define two functional fusion-specific TCRs, one of which has strong anti-tumor activity in vivo. Together, our results provide insights into the fragmented nature of neoantigen-specific repertoires in humans and indicate routes for clinical development of successful immunotherapies for FLC.


Subject(s)
Carcinoma, Hepatocellular , Humans , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/therapy , Carcinoma, Hepatocellular/pathology , Receptors, Antigen, T-Cell/genetics , T-Lymphocytes/pathology , Cell- and Tissue-Based Therapy , HSP40 Heat-Shock Proteins/genetics , Cyclic AMP-Dependent Protein Kinase Catalytic Subunits/genetics
17.
Cell Tissue Res ; 396(1): 41-55, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38403745

ABSTRACT

Cysteine string protein (CSP) is a member of the DnaJ/Hsp40 family of molecular chaperones. CSP is enriched in neurons, where it mainly localises to synaptic vesicles. Mutations in CSP-encoding genes in flies, worms, mice and humans result in neuronal dysfunction, neurodegeneration and reduced lifespan. Most attention has therefore focused on CSP's neuronal functions, although CSP is also expressed in non-neuronal cells. Here, we used genome editing to fluorescently tag the Caenorhabditis elegans CSP orthologue, dnj-14, to identify which tissues preferentially express CSP and hence may contribute to the observed mutant phenotypes. Replacement of dnj-14 with wrmScarlet caused a strong chemotaxis defect, as seen with other dnj-14 null mutants. In contrast, inserting the reporter in-frame to create a DNJ-14-wrmScarlet fusion protein had no effect on chemotaxis, indicating that C-terminal tagging does not impair DNJ-14 function. WrmScarlet fluorescence appeared most obvious in the intestine, head/pharynx, spermathecae and vulva/uterus in the reporter strains, suggesting that DNJ-14 is preferentially expressed in these tissues. Crossing the DNJ-14-wrmScarlet strain with GFP marker strains confirmed the intestinal and pharyngeal expression, but only a partial overlap with neuronal GFP was observed. DNJ-14-wrmScarlet fluorescence in the intestine was increased in response to starvation, which may be relevant to mammalian CSPα's role in microautophagy. DNJ-14's enrichment in worm reproductive tissues (spermathecae and vulva/uterus) parallels the testis-specific expression of CSPß and CSPγ isoforms in mammals. Furthermore, CSPα messenger RNA is highly expressed in the human proximal digestive tract, suggesting that CSP may have a conserved, but overlooked, function within the gastrointestinal system.


Subject(s)
CRISPR-Cas Systems , Caenorhabditis elegans , HSP40 Heat-Shock Proteins , Male , Animals , Mice , Humans , Caenorhabditis elegans/genetics , Caenorhabditis elegans/metabolism , Tissue Distribution , CRISPR-Cas Systems/genetics , Membrane Proteins/metabolism , Mammals/metabolism
18.
Cell Stress Chaperones ; 29(1): 1-9, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38309209

ABSTRACT

The activity of the Hsp70 molecular chaperone is regulated by a suite of helper co-chaperones that include J-proteins. Studies on J-proteins have historically focused on their expression, localization, and activation of Hsp70. There is growing evidence that the post-translational modifications (PTMs) of chaperones (the chaperone code) fine-tune chaperone function. This mini-review summarizes the current understanding of the role and regulation of PTMs on the major J-proteins Ydj1 and DNAJA1. Understanding these PTMs may provide novel therapeutic avenues for targeting chaperone activity in cancer and neurodegenerative diseases.


Subject(s)
HSP40 Heat-Shock Proteins , Molecular Chaperones , Molecular Chaperones/metabolism , HSP40 Heat-Shock Proteins/metabolism , HSP70 Heat-Shock Proteins/metabolism , Protein Folding , Protein Processing, Post-Translational
19.
Cell Stress Chaperones ; 29(1): 21-33, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38320449

ABSTRACT

J-domain proteins (JDPs) are the largest family of chaperones in most organisms, but much of how they function within the network of other chaperones and protein quality control machineries is still an enigma. Here, we report on the latest findings related to JDP functions presented at a dedicated JDP workshop in Gdansk, Poland. The report does not include all (details) of what was shared and discussed at the meeting, because some of these original data have not yet been accepted for publication elsewhere or represented still preliminary observations at the time.


Subject(s)
HSP70 Heat-Shock Proteins , Molecular Chaperones , HSP70 Heat-Shock Proteins/metabolism , Molecular Chaperones/metabolism , Poland , HSP40 Heat-Shock Proteins/metabolism
20.
Transl Psychiatry ; 14(1): 94, 2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38351068

ABSTRACT

Autophagy, a cellular process where cells degrade and recycle their own components, has garnered attention for its potential role in psychiatric disorders, including schizophrenia (SCZ). This study aimed to construct and validate a new autophagy-related gene (ARG) risk model for SCZ. First, we analyzed differential expressions in the GSE38484 training set, identifying 4,754 differentially expressed genes (DEGs) between SCZ and control groups. Using the Human Autophagy Database (HADb) database, we cataloged 232 ARGs and pinpointed 80 autophagy-related DEGs (AR-DEGs) after intersecting them with DEGs. Subsequent analyses, including metascape gene annotation, pathway and process enrichment, and protein-protein interaction enrichment, were performed on the 80 AR-DEGs to delve deeper into their biological roles and associated molecular pathways. From this, we identified 34 candidate risk AR-DEGs (RAR-DEGs) and honed this list to final RAR-DEGs via a constructed and optimized logistic regression model. These genes include VAMP7, PTEN, WIPI2, PARP1, DNAJB9, SH3GLB1, ATF4, EIF4G1, EGFR, CDKN1A, CFLAR, FAS, BCL2L1 and BNIP3. Using these findings, we crafted a nomogram to predict SCZ risk for individual samples. In summary, our study offers deeper insights into SCZ's molecular pathogenesis and paves the way for innovative approaches in risk prediction, gene-targeted diagnosis, and community-based SCZ treatments.


Subject(s)
Schizophrenia , Humans , Schizophrenia/genetics , Autophagy/genetics , Databases, Factual , Logistic Models , Membrane Proteins , Molecular Chaperones , HSP40 Heat-Shock Proteins
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