The regulation mechanism of ethephon-mediated delaying of postharvest physiological deterioration in cassava storage roots based on quantitative acetylproteomes analysis.

Ethylene plays diverse roles in post-harvest processes of horticultural crops. However, its impact and regulation mechanism on the postharvest physiological deterioration (PPD) of cassava storage roots is unknown. In this study, a notable delay in PPD of cassava storage roots was observed when ethephon was utilized as an ethylene source. Physiological analyses and quantitative acetylproteomes were employed to investigate the regulation mechanism regulating cassava PPD under ethephon treatment. Ethephon was found to enhance the reactive oxygen species (ROS) scavenging system, resulting in a significant decrease in H2O2 and malondialdehyde (MDA) content. The comprehensive acetylome analysis identified 12,095 acetylation sites on 4403 proteins. Subsequent analysis demonstrated that ethephon can regulate the acetylation levels of antioxidant enzymes and members of the energy metabolism pathways. In summary, ethephon could enhance the antioxidant properties and regulate energy metabolism pathways, leading to the delayed PPD of cassava.

Simultaneously improving the activity and thermostability of hyperthermophillic pullulanase by modifying the active-site tunnel and surface lysine.

Pullulanases are important starch-debranching enzymes that mainly hydrolyze the α-1,6-glycosidic linkages in pullulan, starch, and oligosaccharides. Nevertheless, their practical applications are constrained because of their poor activity and low thermostability. Moreover, the trade-off between activity and thermostability makes it challenging to simultaneously improve them. In this study, an engineered pullulanase was developed through reshaping the active-site tunnel and engineering the surface lysine residues using the pullulanase from Pyrococcus yayanosii CH1 (PulPY2). The specific activity of the engineered pullulanase was increased 3.1-fold, and thermostability was enhanced 1.8-fold. Moreover, the engineered pullulanase exhibited 11.4-fold improvement in catalytic efficiency (kcat/Km). Molecular dynamics simulations demonstrated an anti-correlated movement around the entrance of active-site tunnel and stronger interactions between the surface residues in the engineered pullulanase, which would be beneficial to the activity and thermostability improvement, respectively. The strategies used in this study and dynamic evidence for insight into enzyme performance improvement may provide guidance for the activity and thermostability engineering of other enzymes.

Hypertonic saline and heart failure: "sodium-centric" or "chlorine-centric"?

Up to 50% of patients admitted for heart failure (HF) have congestion at discharge despite diagnostic and therapeutic advances. Both persistent congestion and diuretic resistance are associated with worse prognosis. The combination of hypertonic saline and loop diuretic has shown promising results in different studies. However, it has not yet achieved a standardized use, partly because of the great heterogeneity in the concentration of sodium chloride, the dose of diuretic or the amount of sodium in the diet. Classically, the movement of water from the intracellular space due to an increase in extracellular osmolarity has been postulated as the main mechanism involved. However, chloride deficit is postulated as the main up-regulator of plasma volume changes, and its correction may be the main mechanism involved. This "chloride centric" approach to heart failure opens the door to therapeutic strategies that would include diuretics to correct hypochloremia, as well as sodium free chloride supplementation.

KAT7 Suppresses Tumorigenesis in Clear Cell Renal Cell Carcinoma (ccRCC) by Regulating Cell Cycle and Ferroptosis Sensitivity.

Clear cell renal cell carcinoma (ccRCC) is one of the most aggressive malignancies in the urological system, known for its high immunogenicity. However, its pathogenesis remains unclear. This study utilized bioinformatics algorithms and in vitro experiments to investigate the role of KAT7 in ccRCC. The results indicate that KAT7 is significantly downregulated in ccRCC tissues and cell lines, which is linked to distant metastasis and unfavorable outcomes in ccRCC patients. Overexpression of KAT7 in vitro notably decreased the proliferation, migration, and invasion of renal cancer cells and inhibited Epithelial-Mesenchymal Transition (EMT). Additionally, Gene Set Enrichment Analysis (GSEA) demonstrated that KAT7-related gene functions are associated with cell cycle and ferroptosis transcription factors. Treatment with a KAT7 acetylation inhibitor in ccRCC cell lines reversed the S phase arrest caused by KAT7 overexpression. Similarly, ferroptosis inhibitors alleviated ferroptosis induced by overexpressed KAT7. In conclusion, the findings suggest that KAT7 acts as a tumor suppressor in ccRCC by modulating the cell cycle and ferroptosis sensitivity, underscoring its potential as a therapeutic target and prognostic biomarker for renal cell carcinoma patients.

Lactococcus lactis KF140 Ameliorates Nonalcoholic Fatty Liver Disease Induced by Nε-Carboxymethyl-Lysine and High-Fat Diet.

SCOPE: Long-term consumption of excessive dietary advanced glycation end-products such as Nε-carboxymethyl-lysine (CML), which are produced by the Maillard reaction during food thermal processing, leads to nonalcoholic fatty liver disease (NAFLD) along with high fat consumption. The study previously finds that administration of Lactococcus lactis KF140 (LL-KF140) detoxifies CML by decreasing CML absorption both in a rat model and clinical trial. METHODS AND RESULTS: The present study evaluates the ameliorative effect of LL-KF140 on NAFLD and fatty liver-related biomarkers in a mouse model induced by CML and high fat. LL-KF140 is orally administered to mice at a concentration of 1 × 107 or 1 × 108 colony-forming unit (CFU) per mouse for 8 weeks. LL-KF140 administration ameliorates the NAFLD-related symptoms by reducing body weight and fat mass gain along with levels of serum aspartate transaminase, alanine transferase, and lipids as well as glucose intolerance and insulin resistance in CML-treated mice. In addition, histological analysis including staining and western blotting shows that LL-KF140 suppresses the lipogenesis pathway and CML absorption, thereby suppressing CML-induced NAFLD. CONCLUSION: These findings suggest that LL-KF140 attenuates dietary CML-induced NAFLD by suppressing the de novo lipogenesis pathway, and it may be used as a probiotic strain.

Integrating Metabolic Oligosaccharide Engineering and SPAAC Click Chemistry for Constructing Fibrinolytic Cell Surfaces.

To effectively solve the problem of significant loss of transplanted cells caused by thrombosis during cell transplantation, this study simulates the human fibrinolytic system and combines metabolic oligosaccharide engineering with strain-promoted azide-alkyne cycloaddition (SPAAC) click chemistry to construct a cell surface with fibrinolytic activity. First, a copolymer (POL) of oligoethylene glycol methacrylate (OEGMA) and 6-amino-2-(2-methylamido)hexanoic acid (Lys) was synthesized by reversible addition-fragmentation chain transfer (RAFT) copolymerization, and the dibenzocyclooctyne (DBCO) functional group was introduced into the side chain of the copolymer through an active ester reaction, resulting in a functionalized copolymer DBCO-PEG4-POL with ε-lysine ligands. Then, azide functional groups were introduced onto the surface of HeLa model cells through metabolic oligosaccharide engineering, and DBCO-PEG4-POL was further specifically modified onto the surface of HeLa cells via the SPAAC "click" reaction. In vitro investigations revealed that compared with unmodified HeLa cells, modified cells not only resist the adsorption of nonspecific proteins such as fibrinogen and human serum albumin but also selectively bind to plasminogen in plasma while maintaining good cell viability and proliferative activity. More importantly, upon the activation of adsorbed plasminogen into plasmin, the modified cells exhibited remarkable fibrinolytic activity and were capable of promptly dissolving the primary thrombus formed on their surfaces. This research not only provides a novel approach for constructing transplantable cells with fibrinolytic activity but also offers a new perspective for effectively addressing the significant loss of transplanted cells caused by thrombosis.

Insight into the mechanism of the aggregation behavior of wheat protein modulated by l-lysine under microwave irradiation.

This study explored the mechanism of l-lysine intervention in wheat gluten protein (WG) gel formation under a microwave (MW) field. The results showed that the MW treatment had higher ζ-potential values at the same heating rate. After adding l-lysine, the solution conductivity and dielectric loss were significantly increased. Moreover, the WG gel strength enhanced 4.40% under the MW treatment. The Fourier spectra showed that the α-helix content was decreased 13.78% with the addition of lysine. The ultraviolet absorption spectra and fluorescence spectra indicated that MW irradiation impacted the interactions between WG molecules more effectively than the water bath heating, promoting the denaturation and unfolding of the protein structure. In addition, scanning electron microscopy analysis showed that the incorporation of lysine promoted an ordered network structure formation of the protein, which enhanced the gel properties. This indicated that the zwitterion of l-lysine played a regulatory role in the aggregation of proteins in the MW field.

Characteristics of soy films as affected by transglutaminase cross-linking and inclusions of pectin and protein enhancers.

Previously, we showed that water extract (soymilk, except pH was increased to 8 from 6.5) of whole soybean could be used directly as a raw material for producing edible soy films by deposition of the film-forming solution (soy extract with enhancers). However, the strength of such soy films needed improvement because they were weak. The purpose of this study was to investigate how transglutaminase (TG) cross-linking reactions and film enhancers, including pectin (low- and high-methoxyl pectin), whey protein isolate (WPI), and soy protein isolate (SPI), improve the physical properties of soy films. Soy films prepared with TG had tensile strength (TS) of 3.01 MPa and puncture strength (PS) of 0.78 MPa, which were higher by as much as 51% and 30% than that of soy films without TG treatment, respectively. Pectin showed significant effects on the mechanical properties of TG-added soy films in terms of TS, PS, and % elongation. On the other hand, only TS and PS were increased by the addition of WPI or SPI. Heat curing had a significant effect on soy film's physical properties. TG treatment significantly reduced film solubility when soaked in water and various levels of acid (vinegar) and base (baking soda) solutions. Under the experimental conditions of 35 unit TG and 28 min of reaction, the degrees of cross-linking were evidenced by the disappearance of individual protein subunits, except the basic subunit of glycinin, and the reduction of 21% of lysine residues of the proteins. HIGHLIGHTS: Edible soy films were made with transglutaminase and about 21% lysine cross-linked. The mechanical strength of soy films was increased by incorporating film enhancers. Transglutaminase enhanced the mechanical properties of soy films.

Functional Linkers Support Targeting of Multivalent Tweezers to Taspase1.

Taspase 1 is a unique protease not only pivotal for embryonic development but also implicated in leukemias and solid tumors. As such, this enzyme is a promising while still challenging therapeutic target, and with its protein structure featuring a flexible loop preceding the active site a versatile model system for drug development. Supramolecular ligands provide a promising complementary approach to traditional small-molecule inhibitors. Recently, the multivalent arrangement of molecular tweezers allowed the successful targeting of Taspase 1's surface loop. With this study we now want to take the next logic step und utilize functional linker systems that not only allow the implementation of novel properties but also engage in protein surface binding. Consequently, we chose two different linker types differing from the original divalent assembly: a backbone with aggregation-induced emission (AIE) properties to enable monitoring of binding and a calix[4]arene scaffold initially pre-positioning the supramolecular binding units. With a series of four AIE-equipped ligands with stepwise increased valency we demonstrated that the functionalized AIE linkers approach ligand binding affinities in the nanomolar range and allow efficient proteolytic inhibition of Taspase 1. Moreover, implementation of the calix[4]arene backbone further enhanced the ligands' inhibitory potential, pointing to a specific linker contribution.

Bacillaceae serine proteases and Streptomyces epsilon-poly-L-lysine synergistically inactivate Caliciviridae by inhibiting RNA genome release.

Human norovirus (HuNoV) is an enteric infectious pathogen belonging to the Caliciviridae family that causes occasional epidemics. Circulating alcohol-tolerant viral particles that are readily transmitted via food-borne routes significantly contribute to the global burden of HuNoV-induced gastroenteritis. Moreover, contact with enzymes secreted by other microorganisms in the environment can impact the infectivity of viruses. Hence, understanding the circulation dynamics of Caliciviridae is critical to mitigating epidemics. Accordingly, in this study, we screened whether environmentally abundant secretase components, particularly proteases, affect Caliciviridae infectivity. Results showed that combining Bacillaceae serine proteases with epsilon-poly-L-lysine (EPL) produced by Streptomyces-a natural antimicrobial-elicited anti-Caliciviridae properties, including against the epidemic HuNoV GII.4_Sydney_2012 strain. In vitro and in vivo biochemical and virological analyses revealed that EPL has two unique synergistic viral inactivation functions. First, it maintains an optimal pH to promote viral surface conformational changes to the protease-sensitive structure. Subsequently, it inhibits viral RNA genome release via partial protease digestion at the P2 and S domains in the VP1 capsid. This study provides new insights regarding the high-dimensional environmental interactions between bacteria and Caliciviridae, while promoting the development of protease-based anti-viral disinfectants.

[An enrichment strategy based on hydrophobic tagging and reversed-phase chromatographic separation for the analysis of lysine-containing peptides].

Lysine (K) is widely used in the design of lysine-targeted crosslinkers, structural elucidation of protein complexes, and analysis of protein-protein interactions. In "shotgun" proteomics, which is based on liquid chromatography-tandem mass spectrometry (LC-MS/MS), proteins from complex samples are enzymatically digested, generating thousands of peptides and presenting significant challenges for the direct analysis of K-containing peptides. In view of the lack of effective methods for the enrichment of K-containing peptides, this work developed a method which based on a hydrophobic-tag-labeling reagent C10-S-S-NHS and reversed-phase chromatography (termed as HYTARP) to achieve the efficient enrichment and identification of K-containing peptides from complex samples. The C10-S-S-NHS synthesized in this work successfully labeled standard peptides containing various numbers of K and the labeling efficiency achieved up to 96% for HeLa cell protein tryptic digests. By investigating the retention behavior of these labeled peptides in C18 RP column, we found that most K-labeled peptides were eluted once when acetonitrile percentage reached 57.6% (v/v). Further optimization of the elution gradient enabled the efficient separation and enrichment of the K-labeled peptides in HeLa digests via a stepwise elution gradient. The K-labeled peptides accounted for 90% in the enriched peptides, representing an improvement of 35% compared with the number of peptides without the enrichment. The dynamic range of proteins quantified from the enriched K-containing peptides spans 5-6 orders of magnitude, and realized the detection of low-abundance proteins in the complex sample. In summary, the HYTARP strategy offers a straightforward and effective approach for reducing sample complexity and improving the identification coverage of K-containing peptides and low-abundance proteins.

Expansion of the phenotypic spectrum of KARS1-related disorders to include arthrogryposis multiplex congenita and summary of experiences with lysine supplementation.

There are currently multiple disorders of aminoacyl-tRNA synthetases described, including KARS1-related disorder resulting from dysfunctional lysyl-tRNA synthetases. In this report, we describe four novel KARS1 variants in three affected individuals, two of whom displayed arthrogryposis-like phenotypes, suggestive of phenotypic expansion. We also highlight subjective clinical improvement in one subject following lysine supplementation in conjunction with a protein-fortified diet, suggesting its potential as a novel treatment modality for KARS1-related disorders. This report offers additional insight into the etiology and management of KARS1-related disorders and expands our ability to provide guidance to affected individuals and their families.

Lysine acetylproteome analysis reveals the lysine acetylation in developing fruit and a key acetylated protein involved in sucrose accumulation in Rosa roxburghii Tratt.

Lysine acetylation is a common post-translational modification of proteins in plants. Rosa roxburghii Tratt. is an economically important fruit tree known for its high nutritional value. However, the characteristics of acetylome-related proteins during fruit development in this crop remain unknown. This study aimed to explore the global acetylproteome of R. roxburghii fruit to identify key lysine-acetylated proteins associated with its quality traits. A total of 4280 acetylated proteins were identified, among them, 981 proteins exhibited differential acetylation (DA) while 19 proteins showed increased acetylation level consistently on individual sites. Functional classification revealed that these DA proteins were primarily associated with central metabolic pathways, carbohydrate metabolism, terpenoids and polyketides metabolism, lipid metabolism, and amino acid metabolism, highlighting the importance of lysine acetylation in fruit quality formation. Notably, the most significant up-regulated acetylation occurred in sucrose synthase (SuS1), a key enzyme in sucrose biosynthesis. Enzyme assays, RNA-seq and proteome analysis indicated that SuS activity, which was independent of its transcriptome and proteome level, may be enhanced by up-acetylation, ultimately increasing sucrose accumulation. Thus, these findings offer a better understanding of the global acetylproteome of R. roxburghii fruit, while also uncover a novel mechanism of acetylated SuS-mediated in sucrose metabolism in plant. SIGNIFICANCE: Rosa roxburghii Tratt. is an important horticultural crop whose commercial value is closely linked to its fruit quality. Acetylation modification is a post-translational mechanism observed in plants, which regulates the physiological functions and metabolic fluxes involved in various biological processes. The regulatory mechanism of lysine acetylation in the fruit quality formation in perennial woody plants has not been fully elucidated, while most of the research has primarily focused on annual crops. Therefore, this study, for the first time, uses Rosaceae fruits as the research material to elucidate the regulatory role of lysine-acetylated proteins in fruit development, identify key metabolic processes influencing fruit quality formation, and provide valuable insights for cultivation strategies.

Lactylated Apolipoprotein C-II Induces Immunotherapy Resistance by Promoting Extracellular Lipolysis.

Mortality rates due to lung cancer are high worldwide. Although PD-1 and PD-L1 immune checkpoint inhibitors boost the survival of patients with non-small-cell lung cancer (NSCLC), resistance often arises. The Warburg Effect, which causes lactate build-up and potential lysine-lactylation (Kla), links immune dysfunction to tumor metabolism. The role of non-histone Kla in tumor immune microenvironment and immunotherapy remains to be clarified. Here, global lactylome profiling and metabolomic analyses of samples from patients with NSCLC is conducted. By combining multi-omics analysis with in vitro and in vivo validation, that intracellular lactate promotes extracellular lipolysis through lactyl-APOC2 is revealed. Mechanistically, lactate enhances APOC2 lactylation at K70, stabilizing it and resulting in FFA release, regulatory T cell accumulation, immunotherapy resistance, and metastasis. Moreover, the anti-APOC2K70-lac antibody that sensitized anti-PD-1 therapy in vivo is developed. This findings highlight the potential of anti lactyl-APOC2-K70 approach as a new combination therapy for sensitizing immunotherapeutic responses.

Biomolecule-grafted GO enhanced the mechanical and biological properties of 3D printed PLA scaffolds with TPMS porous structure.

Graphene oxide (GO) exhibits excellent mechanical strength and modulus. However, its effectiveness in mechanically reinforcing polymer materials is limited due to issues with interfacial bonding and dispersion arising from differences in the physicochemical properties between GO and polymers. Surface modification using coupling agents is an effective method to improve the bonding problem between polymer and GO, but there may be biocompatibility issues when used in the biomedical field. In this study, the biomolecule L-lysine, was applied to improve the interfacial bonding and dispersion of GO in polylactic acid (PLA) without compromising biocompatibility. The PLA/L-lysine-modified GO (PLA/L-GO) bone scaffold with triply periodic minimal surface (TPMS) structure was prepared using fused deposition modeling (FDM). The FTIR results revealed successful grafting of L-lysine onto GO through the reaction between their -COOH and -NH2 groups. The macroscopic and microscopic morphology characterization indicated that the PLA/L-GO scaffolds exhibited an characteristics of dynamic diameter changes, with good interlayer bonding. It was noteworthy that the L-lysine modification promoted the dispersion of GO and the interfacial bonding with the PLA matrix, as characterized by SEM. As a result, the PLA/0.1L-GO scaffold exhibited higher compressive strength (13.2 MPa) and elastic modulus (226.8 MPa) than PLA/0.1GO. Moreover, PLA/L-GO composite scaffold exhibited superior biomineralization capacity and cell response compared to PLA/GO. In summary, L-lysine not only improved the dispersion and interfacial bonding of GO with PLA, enhancing the mechanical properties, but also improved the biological properties. This study suggests that biomolecules like L-lysine may replace traditional modifiers as an innovative bio-modifier to improve the performance of polymer/inorganic composite biomaterials.

Structure-based mapping of the histone-binding pocket of KDM4D using functionalized tetrazole and pyridine core compounds.

KDM4 histone demethylases became an exciting target for inhibitor development as the evidence linking them directly to tumorigenesis mounts. In this study, we set out to better understand the binding cavity using an X-ray crystallographic approach to provide a detailed landscape of possible interactions within the under-investigated region of KDM4. Our design strategy was based on utilizing known KDM binding motifs, such as nicotinic acid and tetrazolylhydrazides, as core motifs that we decided to enrich with flexible tails to map the distal histone binding site. The resulting X-ray structures of the novel compounds bound to KDM4D, a representative of the KDM4 family, revealed the interaction pattern with distal residues in the histone-binding site. The most prominent protein rearrangement detected upon ligand binding is the loop movement that blocks the accessibility to the histone binding site. Apart from providing new sites that potential inhibitors can target, the novel compounds may prove helpful in exploring the capacity of ligands to bind in sites distal to the cofactor-binding site of other KDMs or 2-oxoglutarate (2OG)-dependent oxygenases. The case study proves that combining a strong small binding motif with flexible tails to probe the binding pocket will facilitate lead discovery in classical drug-discovery campaigns, given the ease of accessing X-ray quality crystals.

Protein lysine crotonylation in cellular processions and disease associations.

Protein lysine crotonylation (Kcr) is one conserved form of posttranslational modifications of proteins, which plays an important role in a series of cellular physiological and pathological processes. Lysine ε-amino groups are the primary sites of such modification, resulting in four-carbon planar lysine crotonylation that is structurally and functionally distinct from the acetylation of these residues. High levels of Kcr modifications have been identified on both histone and non-histone proteins. The present review offers an update on the research progression regarding protein Kcr modifications in biomedical contexts and provides a discussion of the mechanisms whereby Kcr modification governs a range of biological processes. In addition, given the importance of protein Kcr modification in disease onset and progression, the potential viability of Kcr regulators as therapeutic targets is elucidated.

KMT2D-mediated H3K4me1 recruits YBX1 to facilitate triple-negative breast cancer progression through epigenetic activation of c-Myc.

BACKGROUND: Lysine methyltransferase 2D (KMT2D) mediates mono-methylation of histone H3 lysine 4 (H3K4me1) in mammals. H3K4me1 mark is involved in establishing an active chromatin structure to promote gene transcription. However, the precise molecular mechanism underlying the KMT2D-mediated H3K4me1 mark modulates gene expression in triple-negative breast cancer (TNBC) progression is unresolved. METHODS AND RESULTS: We recognized Y-box-binding protein 1 (YBX1) as a "reader" of the H3K4me1 mark, and a point mutation of YBX1 (E121A) disrupted this interaction. We found that KMT2D and YBX1 cooperatively promoted cell growth and metastasis of TNBC cells in vitro and in vivo. The expression levels of KMT2D and YBX1 were both upregulated in tumour tissues and correlated with poor prognosis for breast cancer patients. Combined analyses of ChIP-seq and RNA-seq data indicated that YBX1 was co-localized with KMT2D-mediated H3K4me1 in the promoter regions of c-Myc and SENP1, thereby activating their expressions in TNBC cells. Moreover, we demonstrated that YBX1 activated the expressions of c-Myc and SENP1 in a KMT2D-dependent manner. CONCLUSION: Our results suggest that KMT2D-mediated H3K4me1 recruits YBX1 to facilitate TNBC progression through epigenetic activation of c-Myc and SENP1. These results together unveil a crucial interplay between histone mark and gene regulation in TNBC progression, thus providing novel insights into targeting the KMT2D-H3K4me1-YBX1 axis for TNBC treatment. HIGHLIGHTS: YBX1 is a KMT2D-mediated H3K4me1-binding effector protein and mutation of YBX1 (E121A) disrupts its binding to H3K4me1. KMT2D and YBX1 cooperatively promote TNBC proliferation and metastasis by activating c-Myc and SENP1 expression in vitro and in vivo. YBX1 is colocalized with H3K4me1 in the c-Myc and SENP1 promoter regions in TNBC cells and increased YBX1 expression predicts a poor prognosis in breast cancer patients.

Sodium Crotonate Alleviates Diabetic Kidney Disease Partially Via the Histone Crotonylation Pathway.

Diabetic kidney disease (DKD) is a common microvascular complication of diabetes, inflammation and fibrosis play an important role in its progression. Histone lysine crotonylation (Kcr) was first identified as a new type of post-translational modification in 2011. In recent years, prominent progress has been made in the study of sodium crotonate (NaCr) and histone Kcr in kidney diseases. However, the effects of NaCr and NaCr-induced Kcr on DKD remain unclear. In this study, db/db mice and high glucose-induced human tubular epithelial cells (HK-2) were used respectively, and exogenous NaCr and crotonoyl-coenzyme A (Cr-CoA) as intervention reagents, histone Kcr and DKD-related indicators were detected. The results confirmed that NaCr had an antidiabetic effect and decreased blood glucose and serum lipid levels and alleviated renal function and DKD-related inflammatory and fibrotic damage. NaCr also induced histone Kcr and histone H3K18 crotonylation (H3K18cr). However, NaCr and Cr-CoA-induced histone Kcr and protective effects were reversed by inhibiting the activity of Acyl-CoA synthetase short-chain family member 2 (ACSS2) or histone acyltransferase P300 in vitro. In summary, our data reveal that NaCr may mitigate DKD via an antidiabetic effect as well as through ACSS2 and P300-induced histone Kcr, suggesting that Kcr may be the potential molecular mechanism and prevention target of DKD.

Vibrio alginolyticus PEPCK Mediates Florfenicol Resistance through Lysine Succinylation Modification.

Protein succinylation modification is a common post-translational modification (PTM) that plays an important role in bacterial metabolic regulation. In this study, quantitative analysis was conducted on the succinylated proteome of wild-type and florfenicol-resistant Vibrio alginolyticus to investigate the mechanism of succinylation regulating antibiotic resistance. Bioinformatic analysis showed that the differentially succinylated proteins were mainly enriched in energy metabolism, and it was found that the succinylation level of phosphoenolpyruvate carboxyl kinase (PEPCK) was highly expressed in the florfenicol-resistant strain. Site-directed mutagenesis was used to mutate the lysine (K) at the succinylation site of PEPCK to glutamic acid (E) and arginine (R), respectively, to investigate the function of lysine succinylation of PEPCK in the florfenicol resistance of V. alginolyticus. The detection of site-directed mutagenesis strain viability under florfenicol revealed that the survival rate of the E mutant was significantly higher than that of the R mutant and wild type, indicating that succinylation modification of PEPCK protein may affect the resistance of V. alginolyticus to florfenicol. This study indicates the important role of PEPCK during V. alginolyticus antibiotic-resistance evolution and provides a theoretical basis for the prevention and control of vibriosis and the development of new antibiotics.