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1.
Cell Rep ; 43(8): 114629, 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39146183

ABSTRACT

In mice, the first liver-resident macrophages, known as Kupffer cells (KCs), are thought to derive from yolk sac (YS) hematopoietic progenitors that are specified prior to the emergence of the hematopoietic stem cell (HSC). To investigate human KC development, we recapitulated YS-like hematopoiesis from human pluripotent stem cells (hPSCs) and transplanted derivative macrophage progenitors into NSG mice previously humanized with hPSC-liver sinusoidal endothelial cells (LSECs). We demonstrate that hPSC-LSECs facilitate stable hPSC-YS-macrophage engraftment for at least 7 weeks. Single-cell RNA sequencing (scRNA-seq) of engrafted YS-macrophages revealed a homogeneous MARCO-expressing KC gene signature and low expression of monocyte-like macrophage genes. In contrast, human cord blood (CB)-derived macrophage progenitors generated grafts that contain multiple hematopoietic lineages in addition to KCs. Functional analyses showed that the engrafted KCs actively perform phagocytosis and erythrophagocytosis in vivo. Taken together, these findings demonstrate that it is possible to generate human KCs from hPSC-derived, YS-like progenitors.


Subject(s)
Cell Differentiation , Endothelial Cells , Kupffer Cells , Liver , Pluripotent Stem Cells , Humans , Kupffer Cells/metabolism , Kupffer Cells/cytology , Pluripotent Stem Cells/metabolism , Pluripotent Stem Cells/cytology , Endothelial Cells/metabolism , Endothelial Cells/cytology , Animals , Liver/cytology , Liver/metabolism , Mice , Phagocytosis , Hematopoiesis
2.
Otolaryngol Head Neck Surg ; 168(3): 551-553, 2023 03.
Article in English | MEDLINE | ID: mdl-35608908

ABSTRACT

In 1835, Peter Parker, an American surgeon and Presbyterian minister, established a hospital in Guangzhou and became the first Western head and neck surgeon in China. While Parker documented his most interesting cases in his journals, he also commissioned oil paintings of these patients from Lam Qua (), a prominent Chinese artist trained in British academic painting. Lam Qua produced 86 portraits of Dr Parker's patients, providing insight into not only the treatment of head and neck tumors but also the introduction of Western artistic techniques to 19th-century China. Parker's pioneering surgical accomplishments and Lam Qua's portraits document the role of art and medicine in America's cultural influence in Asia.


Subject(s)
Medicine , Paintings , Surgeons , United States , Humans , History, 19th Century , China , Paintings/history , Asia
3.
Front Neurosci ; 16: 1058359, 2022.
Article in English | MEDLINE | ID: mdl-36711134

ABSTRACT

Background: Schizophrenia (SCZ) is a heterogeneous psychiatric disorder, with significant contribution from genetic factors particularly for chronic cases with negative symptoms and cognitive deficits. To date, Genome Wide Association Studies (GWAS) and exome sequencing have associated SCZ with a number of single nucleotide polymorphisms (SNPs) and copy number variants (CNVs), but there is still missing heritability. Medium-sized structural variants (SVs) are difficult to detect using SNP arrays or second generation sequencing, and may account for part of the missing heritability of SCZ. Aims and objectives: To identify SVs associated with severe chronic SCZ across the whole genome. Study design: 10 multiplex families with probands suffering from chronic SCZ with negative symptoms and cognitive deficits were recruited, with all their affected members demonstrating uni-lineal inheritance. Control subjects comprised one affected member from the affected lineage, and unaffected members from each paternal and maternal lineage. Methods: Third generation sequencing was applied to peripheral blood samples from 10 probands and 5 unaffected controls. Bioinformatic tools were used to identify SVs from the long sequencing reads, with confirmation of findings in probands by short-read Illumina sequencing, Sanger sequencing and visual manual validation with Integrated Genome Browser. Results: In the 10 probands, we identified and validated 88 SVs (mostly in introns and medium-sized), within 79 genes, which were absent in the 5 unaffected control subjects. These 79 genes were enriched in 20 biological pathways which were related to brain development, neuronal migration, neurogenesis, neuronal/synaptic function, learning/memory, and hearing. These identified SVs also showed evidence for enrichment of genes that are highly expressed in the adolescent striatum. Conclusion: A substantial part of the missing heritability in SCZ may be explained by medium-sized SVs detectable only by third generation sequencing. We have identified a number of such SVs potentially conferring risk for SCZ, which implicate multiple brain-related genes and pathways. In addition to previously-identified pathways involved in SCZ such as neurodevelopment and neuronal/synaptic functioning, we also found novel evidence for enrichment in hearing-related pathways and genes expressed in the adolescent striatum.

4.
Psychol Med ; 51(2): 236-243, 2021 01.
Article in English | MEDLINE | ID: mdl-31779726

ABSTRACT

BACKGROUND: A proportion of ex-military personnel who develop mental health and social problems end up in the Criminal Justice System. A government review called for better understanding of pathways to offending among ex-military personnel to improve services and reduce reoffending. We utilised data linkage with criminal records to examine the patterns of offending among military personnel after they leave service and the associated risk (including mental health and alcohol problems) and socio-economic protective factors. METHOD: Questionnaire data from a cohort study of 13 856 randomly selected UK military personnel were linked with national criminal records to examine changes in the rates of offending after leaving service. RESULTS: All types of offending increased after leaving service, with violent offending being the most prevalent. Offending was predicted by mental health and alcohol problems: probable PTSD, symptoms of common mental disorder and aggressive behaviour (verbal, property and threatened or actual physical aggression). Reduced risk of offending was associated with post-service socio-economic factors: absence of debt, stable housing and relationship satisfaction. These factors were associated with a reduced risk of offending in the presence of mental health risk factors. CONCLUSIONS: Ex-military personnel are more likely to commit violent offences after leaving service than other offence-types. Mental health and alcohol problems are associated with increased risk of post-service offending, and socio-economic stability is associated with reduced risk of offending among military veterans with these problems. Efforts to reduce post-service offending should encompass management of socio-economic risk factors as well as mental health.


Subject(s)
Criminals/statistics & numerical data , Military Personnel/statistics & numerical data , Veterans/statistics & numerical data , Adult , Afghan Campaign 2001- , Aggression , Alcohol-Related Disorders/epidemiology , Cohort Studies , Female , Humans , Information Storage and Retrieval , Iraq War, 2003-2011 , Male , Mental Health , Middle Aged , Protective Factors , Risk Factors , Socioeconomic Factors , Stress Disorders, Post-Traumatic/epidemiology , Surveys and Questionnaires , United Kingdom/epidemiology
5.
Commun Biol ; 3(1): 672, 2020 11 13.
Article in English | MEDLINE | ID: mdl-33188360

ABSTRACT

Hematopoietic adaptor containing SH3 and SAM domains-1 (HACS1) is a signaling protein with two juxtaposed protein-protein interaction domains and an intrinsically unstructured region that spans half the sequence. Here, we describe the interaction between the HACS1 SH3 domain and a sequence near the third immunoreceptor tyrosine-based inhibition motif (ITIM3) of the paired immunoglobulin receptor B (PIRB). From surface plasmon resonance binding assays using a mouse and human PIRB ITIM3 phosphopeptides as ligands, the HACS1 SH3 domain and SHP2 N-terminal SH2 domain demonstrated comparable affinities in the micromolar range. Since the PIRB ITIM3 sequence represents an atypical ligand for an SH3 domain, we determined the NMR structure of the HACS1 SH3 domain and performed a chemical shift mapping study. This study showed that the binding site on the HACS1 SH3 domain for PIRB shares many of the same amino acids found in a canonical binding cleft normally associated with polyproline ligands. Molecular modeling suggests that the respective binding sites in PIRB ITIM3 for the HACS1 SH3 domain and the SHP2 SH2 domain are too close to permit simultaneous binding. As a result, the HACS1-PIRB partnership has the potential to amalgamate signaling pathways that influence both immune and neuronal cell fate.


Subject(s)
Adaptor Proteins, Vesicular Transport , Membrane Glycoproteins , Receptors, Immunologic , Adaptor Proteins, Vesicular Transport/chemistry , Adaptor Proteins, Vesicular Transport/genetics , Adaptor Proteins, Vesicular Transport/metabolism , Animals , Binding Sites , Humans , Membrane Glycoproteins/chemistry , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Mice , Models, Molecular , Protein Binding , Receptors, Immunologic/chemistry , Receptors, Immunologic/genetics , Receptors, Immunologic/metabolism , Signal Transduction , src Homology Domains
6.
Trauma Violence Abuse ; 21(3): 586-609, 2020 07.
Article in English | MEDLINE | ID: mdl-29911508

ABSTRACT

BACKGROUND: Research on intimate partner violence (IPV) in the military has tended to focus on military personnel as perpetrators and civilian partners/spouses as victims. However, studies have found high levels of IPV victimization among military personnel. This article systematically reviews studies of the prevalence of self-reported IPV victimization among military populations. METHODS: Searches of four electronic databases (Embase, Medline, PsycINFO, and Web of Science) were supplemented by reference list screening. Meta-analyses of the available data were performed, where possible, using the random effects model. RESULTS: This review included 28 studies with a combined sample of 69,808 military participants. Overall, similar or higher prevalence rates of physical IPV victimization were found among males compared to females and this was supported by a meta-analytic subgroup analysis: pooled prevalence of 21% (95% confidence interval [CI] = [17.4, 24.6]) among males and 13.6% among females (95% CI [9.5, 17.7]). Psychological IPV was the most prevalent type of abuse, in keeping with findings from the general population. There were no studies on sexual IPV victimization among male personnel. Evidence for the impact of military factors, such as deployment or rank, on IPV victimization was conflicting. DISCUSSION: Prevalence rates varied widely, influenced by methodological variation among studies. The review highlighted the lack of research into male IPV victimization in the military and the relative absence of research into impact of IPV. It is recommended that future research disaggregates results by gender and considers the impact of IPV, in order that gender differences can be uncovered.


Subject(s)
Crime Victims/statistics & numerical data , Intimate Partner Violence/statistics & numerical data , Military Personnel/statistics & numerical data , Adult , Disclosure , Emotional Abuse/statistics & numerical data , Female , Humans , Intimate Partner Violence/psychology , Male , Prevalence , Rape/statistics & numerical data , Self Report
7.
Cell Rep ; 27(2): 599-615.e12, 2019 04 09.
Article in English | MEDLINE | ID: mdl-30970261

ABSTRACT

Human pluripotent stem cells (hPSCs) provide an invaluable tool for modeling diseases and hold promise for regenerative medicine. For understanding pluripotency and lineage differentiation mechanisms, a critical first step involves systematically cataloging essential genes (EGs) that are indispensable for hPSC fitness, defined as cell reproduction in this study. To map essential genetic determinants of hPSC fitness, we performed genome-scale loss-of-function screens in an inducible Cas9 H1 hPSC line cultured on feeder cells and laminin to identify EGs. Among these, we found FOXH1 and VENTX, genes that encode transcription factors previously implicated in stem cell biology, as well as an uncharacterized gene, C22orf43/DRICH1. hPSC EGs are substantially different from other human model cell lines, and EGs in hPSCs are highly context dependent with respect to different growth substrates. Our CRISPR screens establish parameters for genome-wide screens in hPSCs, which will facilitate the characterization of unappreciated genetic regulators of hPSC biology.


Subject(s)
Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Gene Expression Regulation/genetics , Genes, Essential/genetics , Pluripotent Stem Cells/metabolism , Cell Differentiation , Humans
8.
Neurology ; 91(5): 234-238, 2018 07 31.
Article in English | MEDLINE | ID: mdl-30061341

ABSTRACT

OBJECTIVE: To enhance residency education by implementing the 6 principles of adult learning theory (ALT) in a large academic neurology residency program. METHODS: We implemented a set of curricular interventions aimed at Resident Education through Adult Learning in Neurology (REAL Neurology), in a large, academic neurology residency program. Interventions included didactic reform, increasing resident-as-teacher activities, and enhancing residents' interaction. The primary outcome was the change in mean Residency In-service Training Examination (RITE) percentile between the preintervention and postintervention cohorts, adjusting for US Medical Licensing Examination step 1 and 2 score. Other analysis included evaluating the effect of the duration of intervention exposure on outcome and evaluating the intervention effect on the proportion of advanced performers. RESULTS: A total of 134 RITE score reports were evaluated (87 preintervention and 47 postintervention). The mean RITE score percentile postintervention was 11.7 points higher than preintervention (adjusted, longitudinal analysis: fit linear mixed model, p < 0.0001). Postgraduate year 3 learners who had 1 and 2 years of exposure scored 13.4 and 18.9 points higher than those with no exposure at all, respectively (analysis of covariance, p = 0.04). The adjusted odds of better performance with REAL Neurology was 5.77 (ordinal logistic regression, 95% confidence interval 2.37-14.07, p < 0.05). CONCLUSION: This study evaluated the efficacy and feasibility of an ALT-based curricular program in neurology education. The results show robust and sustainable benefit for residents in training without imposing a financial or logistical burden on programs. REAL Neurology could serve as a model for curricular reform in other programs across subspecialties.


Subject(s)
Clinical Competence , Internship and Residency/methods , Neurology/education , Neurology/methods , Adult , Cohort Studies , Humans , Internship and Residency/trends , Neurology/trends
9.
Diabetes ; 67(5): 831-840, 2018 05.
Article in English | MEDLINE | ID: mdl-29511026

ABSTRACT

Exercise alone is often ineffective for treating obesity despite the associated increase in metabolic requirements. Decreased nonexercise physical activity has been implicated in this resistance to weight loss, but the mechanisms responsible are unclear. We quantified the metabolic cost of nonexercise activity, or "off-wheel" activity (OWA), and voluntary wheel running (VWR) and examined whether changes in OWA during VWR altered energy balance in chow-fed C57BL/6J mice (n = 12). Energy expenditure (EE), energy intake, and behavior (VWR and OWA) were continuously monitored for 4 days with locked running wheels followed by 9 days with unlocked running wheels. Unlocking the running wheels increased EE as a function of VWR distance. The metabolic cost of exercise (kcal/m traveled) decreased with increasing VWR speed. Unlocking the wheel led to a negative energy balance but also decreased OWA, which was predicted to mitigate the expected change in energy balance by ∼45%. A novel behavioral circuit involved repeated bouts of VWR, and roaming was discovered and represented novel predictors of VWR behavior. The integrated analysis described here reveals that the weight loss effects of voluntary exercise can be countered by a reduction in nonexercise activity.


Subject(s)
Energy Intake/physiology , Energy Metabolism/physiology , Motor Activity/physiology , Physical Conditioning, Animal/physiology , Animals , Behavior, Animal , Calorimetry, Indirect , Male , Mice , Mice, Inbred C57BL , Obesity , Weight Loss
10.
Psychol Med ; 48(13): 2202-2212, 2018 10.
Article in English | MEDLINE | ID: mdl-29254510

ABSTRACT

BACKGROUND: Research into violence among military personnel has not differentiated between stranger- and family-directed violence. While military factors (combat exposure and post-deployment mental health problems) are risk factors for general violence, there has been limited research on their impact on violence within the family environment. This study aims to compare the prevalence of family-directed and stranger-directed violence among a deployed sample of UK military personnel and to explore risk factors associated with both family- and stranger-directed violence. METHOD: This study utilised data from a large cohort study which collected information by questionnaire from a representative sample of randomly selected deployed UK military personnel (n = 6711). RESULTS: The prevalence of family violence immediately following return from deployment was 3.6% and 7.8% for stranger violence. Family violence was significantly associated with having left service, while stranger violence was associated with younger age, male gender, being single, having a history of antisocial behaviour as well as having left service. Deployment in a combat role was significantly associated with both family and stranger violence after adjustment for confounders [adjusted odds ratio (aOR) = 1.92 (1.25-2.94), p = 0.003 and aOR = 1.77 (1.31-2.40), p < 0.001, respectively], as was the presence of symptoms of post-traumatic stress disorder, common mental disorders and aggression. CONCLUSIONS: Exposure to combat and post-deployment mental health problems are risk factors for violence both inside and outside the family environment and should be considered in violence reduction programmes for military personnel. Further research using a validated measurement tool for family violence would improve comparability with other research.


Subject(s)
Aggression , Domestic Violence/statistics & numerical data , Military Personnel/statistics & numerical data , Physical Abuse/statistics & numerical data , Stress Disorders, Post-Traumatic/epidemiology , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , United Kingdom/epidemiology , Young Adult
11.
Soc Psychiatry Psychiatr Epidemiol ; 52(9): 1059-1080, 2017 09.
Article in English | MEDLINE | ID: mdl-28748307

ABSTRACT

PURPOSE: There is growing awareness of the problem of intimate partner violence (IPV) among military populations. IPV victimisation has been shown to be associated with mental disorder. A better understanding of the link between IPV and mental disorder is needed to inform service development to meet the needs of military families. We aimed to systematically review the literature on the association between IPV victimisation and mental health disorders among military personnel. METHODS: Searches of four electronic databases (Embase, Medline, PsycINFO, and Web of Science) were supplemented by reference list screening. Heterogeneity among studies precluded a meta-analysis. RESULTS: Thirteen studies were included. There was stronger evidence for an association between IPV and depression/alcohol problems than between IPV and PTSD. An association between IPV and mental health problems was more frequently found among veterans compared to active duty personnel. However, the link between IPV and alcohol misuse was more consistently found among active duty samples. Finally, among active duty personnel psychological IPV was more consistently associated with depression/alcohol problems than physical/sexual IPV. The review highlighted the lack of research on male IPV victimisation in the military. CONCLUSIONS: There is evidence that the burden of mental health need may be significant among military personnel who are victims of IPV. The influence of attitudes towards gender in the military on research in this area is discussed. Further research is needed to inform development of services and policy to reduce IPV victimisation and the mental health consequences among military personnel.


Subject(s)
Crime Victims/statistics & numerical data , Intimate Partner Violence/statistics & numerical data , Mental Disorders/epidemiology , Military Personnel/psychology , Veterans/psychology , Humans
12.
Aggress Behav ; 43(3): 273-280, 2017 May.
Article in English | MEDLINE | ID: mdl-27775160

ABSTRACT

Large numbers of British and American Reservists have been deployed to operations in Iraq and Afghanistan. Little is known about the impact of deployment and combat exposure on violent behavior in Reservists. The purpose of this study was to determine the prevalence of self-reported violent behavior among a representative sample of United Kingdom Reservists, the risk factors associated with violence and the impact of deployment and combat exposure on violence. This study used data from a large cohort study of randomly selected UK military personnel and included Reservists who were in service at the time of sampling (n = 1710). Data were collected by questionnaires that asked about socio-demographic and military characteristics, pre-enlistment antisocial behavior, deployment experiences, post-deployment mental health, and self-reported interpersonal violent behavior. The prevalence of violence among Reservists was 3.5%. Deployment was found to be a risk factor for violent behavior even after adjustment for confounders. The association with violence was similar for those deployed in either a combat role or non-combat role. Violence was also strongly associated with mental health risk factors (PTSD, common mental disorders, and alcohol misuse). This study demonstrated higher levels of self-reported post-deployment violence in UK Reservists who had served in either Iraq or Afghanistan. Deployment, irrespective of the role was associated with higher levels of violent behavior among Reservists. The results also emphasize the risk of violent behavior associated with post-deployment mental health problems. Aggr. Behav. 43:273-280, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Mental Disorders/epidemiology , Military Personnel/statistics & numerical data , Problem Behavior , Violence/statistics & numerical data , War Exposure/statistics & numerical data , Adult , Afghan Campaign 2001- , Female , Humans , Iraq War, 2003-2011 , Male , Middle Aged , Risk Factors , United Kingdom , Young Adult
13.
BMC Struct Biol ; 16: 14, 2016 09 13.
Article in English | MEDLINE | ID: mdl-27619958

ABSTRACT

BACKGROUND: CASKIN2 is a neuronal signaling scaffolding protein comprised of multiple ankyrin repeats, two SAM domains, and one SH3 domain. The CASKIN2 SH3 domain for an NMR structural determination because its peptide-binding cleft appeared to deviate from the repertoire of aromatic enriched amino acids that typically bind polyproline-rich sequences. RESULTS: The structure demonstrated that two non-canonical basic amino acids (K290/R319) in the binding cleft were accommodated well in the SH3 fold. An K290Y/R319W double mutant restoring the typical aromatic amino acids found in the binding cleft resulted in a 20 °C relative increase in the thermal stability. Considering the reduced stability, we speculated that the CASKIN2 SH3 could be a nonfunctional remnant in this scaffolding protein. CONCLUSIONS: While the NMR structure demonstrates that the CASKIN2 SH3 domain is folded, its cleft has suffered two substitutions that prevent it from binding typical polyproline ligands. This observation led us to additionally survey and describe other SH3 domains in the Protein Data Bank that may have similarly lost their ability to promote protein-protein interactions.


Subject(s)
Adaptor Proteins, Signal Transducing/chemistry , Adaptor Proteins, Signal Transducing/metabolism , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/metabolism , Peptides/metabolism , src Homology Domains , Amino Acid Sequence , Humans , Models, Molecular , Nuclear Magnetic Resonance, Biomolecular , Protein Binding , Protein Folding , Protein Stability , Temperature
14.
Cell Commun Signal ; 14(1): 17, 2016 08 22.
Article in English | MEDLINE | ID: mdl-27549312

ABSTRACT

BACKGROUND: CASKIN2 is a homolog of CASKIN1, a scaffolding protein that participates in a signaling network with CASK (calcium/calmodulin-dependent serine kinase). Despite a high level of homology between CASKIN2 and CASKIN1, CASKIN2 cannot bind CASK due to the absence of a CASK Interaction Domain and consequently, may have evolved undiscovered structural and functional distinctions. RESULTS: We demonstrate that the crystal structure of the Sterile Alpha Motif (SAM) domain tandem (SAM1-SAM2) oligomer from CASKIN2 is different than CASKIN1, with the minimal repeating unit being a dimer, rather than a monomer. Analytical ultracentrifugation sedimentation velocity methods revealed differences in monomer/dimer equilibria across a range of concentrations and ionic strengths for the wild type CASKIN2 SAM tandem and a structure-directed double mutant that could not oligomerize. Further distinguishing CASKIN2 from CASKIN1, EGFP-tagged SAM tandem proteins expressed in Neuro2a cells produced punctae that were distinct both in shape and size. CONCLUSIONS: This study illustrates a new way in which neuronal SAM domains can assemble into large macromolecular assemblies that might concentrate and amplify synaptic responses.


Subject(s)
Adaptor Proteins, Signal Transducing/chemistry , Nerve Tissue Proteins/chemistry , Protein Multimerization , Adaptor Proteins, Signal Transducing/metabolism , Humans , Molecular Dynamics Simulation , Nerve Tissue Proteins/metabolism , Protein Domains
15.
PLoS One ; 11(8): e0161432, 2016.
Article in English | MEDLINE | ID: mdl-27532129

ABSTRACT

Group E members of the SOX transcription factor family include SOX8, SOX9, and SOX10. Preceding the high mobility group (HMG) domain in each of these proteins is a thirty-eight amino acid region that supports the formation of dimers on promoters containing tandemly inverted sites. The purpose of this study was to obtain new structural insights into how the dimerization region functions with the HMG domain. From a mutagenic scan of the dimerization region, the most essential amino acids of the dimerization region were clustered on the hydrophobic face of a single, predicted amphipathic helix. Consistent with our hypothesis that the dimerization region directly contacts the HMG domain, a peptide corresponding to the dimerization region bound a preassembled HMG-DNA complex. Sequence conservation among Group E members served as a basis to identify two surface exposed amino acids in the HMG domain of SOX9 that were necessary for dimerization. These data were combined to make a molecular model that places the dimerization region of one SOX9 protein onto the HMG domain of another SOX9 protein situated at the opposing site of a tandem promoter. The model provides a detailed foundation for assessing the impact of mutations on SOX Group E transcription factors.


Subject(s)
DNA-Binding Proteins/metabolism , HMG-Box Domains/genetics , Models, Molecular , Protein Multimerization/genetics , SOX9 Transcription Factor/genetics , SOX9 Transcription Factor/metabolism , Amino Acid Sequence , Amino Acid Substitution/genetics , Binding Sites/genetics , Dimerization , Electrophoretic Mobility Shift Assay , Humans , Hydrophobic and Hydrophilic Interactions , Molecular Docking Simulation , Promoter Regions, Genetic
16.
PLoS One ; 8(6): e65605, 2013.
Article in English | MEDLINE | ID: mdl-23799029

ABSTRACT

AIDA1 links persistent chemical signaling events occurring at the neuronal synapse with global changes in gene expression. Consistent with its role as a scaffolding protein, AIDA1 is composed of several protein-protein interaction domains. Here we report the NMR structure of the carboxy terminally located phosphotyrosine binding domain (PTB) that is common to all AIDA1 splice variants. A comprehensive survey of peptides identified a consensus sequence around an NxxY motif that is shared by a number of related neuronal signaling proteins. Using peptide arrays and fluorescence based assays, we determined that the AIDA1 PTB domain binds amyloid protein precursor (APP) in a similar manner to the X11/Mint PTB domain, albeit at reduced affinity (∼10 µM) that may allow AIDA1 to effectively sample APP, as well as other protein partners in a variety of cellular contexts.


Subject(s)
Amyloid beta-Protein Precursor/chemistry , Carrier Proteins/chemistry , Peptide Fragments/chemistry , Amino Acid Sequence , Binding Sites , Circular Dichroism , Conserved Sequence , Humans , Hydrophobic and Hydrophilic Interactions , Intracellular Signaling Peptides and Proteins , Ligands , Molecular Docking Simulation , Molecular Sequence Data , Nuclear Magnetic Resonance, Biomolecular , Protein Binding , Protein Interaction Domains and Motifs , Protein Structure, Secondary , Sequence Homology, Amino Acid , Solubility , Structural Homology, Protein
17.
Biochemistry ; 52(21): 3612-4, 2013 May 28.
Article in English | MEDLINE | ID: mdl-23672713

ABSTRACT

A cluster of genes in the exoxis region of bacteriophage λ are capable of inhibiting the initiation of DNA synthesis in Escherichia coli. The most indispensible gene in this region is ea8.5. Here, we report the nuclear magnetic resonance structures of two ea8.5 orthologs from enteropathogenic E. coli and Pseudomonas putida prophages. Both proteins are characterized by a fused homeodomain/zinc-finger fold that escaped detection by primary sequence search methods. While these folds are both associated with a nucleic acid binding function, the amino acid composition suggests otherwise, leading to the possibility that Ea8.5 associates with other viral and host proteins.


Subject(s)
Bacteriophage lambda/chemistry , Homeodomain Proteins/chemistry , Prophages/chemistry , Viral Proteins/chemistry , Zinc Fingers , Amino Acid Sequence , Coliphages/chemistry , Molecular Sequence Data , Nuclear Magnetic Resonance, Biomolecular , Protein Conformation , Pseudomonas Phages/chemistry , Sequence Homology, Amino Acid
18.
FEBS Lett ; 584(20): 4351-6, 2010 Oct 22.
Article in English | MEDLINE | ID: mdl-20875822

ABSTRACT

The Cajal body is a dynamic eukaryotic nuclear organelle that is known primarily as an organizational center for the assembly of snRNAs involved in transcript splicing. One of the most critical components of the Cajal body is the scaffolding protein, Coilin. Here, we demonstrate by NMR methods that the carboxy-terminal region contains a Tudor domain. The Tudor domain is atypical due to the presence of several unstructured loops, one greater than thirty amino acids in length. Tudor domains have been noted previously to bind DNA, RNA and modified amino acids. The absence of these sequence and structural signatures in the Coilin Tudor domain supporting these established functions suggests an alternative role.


Subject(s)
Models, Molecular , Nuclear Proteins/chemistry , Protein Structure, Secondary , Protein Structure, Tertiary , Amino Acid Sequence , Binding Sites/genetics , Circular Dichroism , Humans , Magnetic Resonance Spectroscopy/methods , Molecular Sequence Data , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Sequence Homology, Amino Acid , Solutions
19.
Phytother Res ; 24(8): 1202-6, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20135638

ABSTRACT

Antibiotic resistance is increasing resulting in a decreasing number of fully active antimicrobial agents available to treat infections with multi-drug resistant (MDR) bacteria. Herbal medicines may offer alternative treatment options. A direct inoculation method simulating the standard disc diffusion assay was developed to determine in vitro antimicrobial activity of sixty herbal extracts against MDR-Acinetobacter baumannii (A. baumannii). Eighteen herbal extracts inhibited MDR-A. baumannii on agar plates, although the magnitude and quality of bacterial inhibition differed considerably among the antibacterial herbal extracts. Next, minimal inhibitory concentration (MIC) of these antibacterial herbal extracts was calculated using a broth microdilution assay. For most herbal extracts, the larger the zone of inhibition on agar plates, the lower the MIC. In general, hetero-resistance on agar plates correlated with higher MIC. The skip well phenomenon was seen with two herbal extracts. In conclusion, 30% of the screened herbal extracts demonstrated in vitro antibacterial activity against MDR-A. baumannii using similar rigorous testing methods as those commonly employed for assessing antimicrobial activity of synthetic antibacterial agents. Characterization of a specific compound conferring this antibacterial activity of the herbal extracts may help to identify novel antimicrobial agents active against highly resistant bacteria.


Subject(s)
Acinetobacter baumannii/drug effects , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Plant Extracts/pharmacology , Microbial Sensitivity Tests
20.
J Mol Biol ; 392(5): 1168-77, 2009 Oct 09.
Article in English | MEDLINE | ID: mdl-19666031

ABSTRACT

The neuronal scaffolding protein AIDA-1 is believed to act as a convener of signals arising at postsynaptic densities. Among the readily identifiable domains in AIDA-1, two closely juxtaposed sterile alpha motif (SAM) domains and a phosphotyrosine binding domain are located within the C-terminus of the longest splice variant and exclusively in four shorter splice variants. As a first step towards understanding the possible emergent properties arising from this assembly of ligand binding domains, we have used NMR methods to solve the first structure of a SAM domain tandem. Separated by a 15-aa linker, the two SAM domains are fused in a head-to-tail orientation that has been observed in other hetero- and homotypic SAM domain structures. The basic nuclear import signal for AIDA-1 is buried at the interface between the two SAM domains. An observed disparity between the thermal stabilities of the two SAM domains suggests a mechanism whereby the second SAM domain decouples from the first SAM domain to facilitate translocation of AIDA-1 to the nucleus.


Subject(s)
Carrier Proteins/chemistry , Carrier Proteins/metabolism , Cell Nucleus/metabolism , Nuclear Localization Signals , Active Transport, Cell Nucleus , Intracellular Signaling Peptides and Proteins , Models, Molecular , Nuclear Magnetic Resonance, Biomolecular , Protein Structure, Tertiary
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