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1.
Int J Ment Health Syst ; 15(1): 33, 2021 Apr 14.
Article in English | MEDLINE | ID: mdl-33853658

ABSTRACT

BACKGROUND: Psychological safety-speaking up about ideas and concerns, free from interpersonal risk-are essential to the high-risk environment, such as healthcare settings. Psychologically safe working is particularly important in mental health where recovery-oriented approaches rely on collaborative efforts of interprofessional teams to make complex decisions. Much research focuses on antecedents and outcomes associated with psychological safety, but little focus on the practical steps for how to increase psychological safety across and at different levels of a healthcare organisation. AIMS: We explore how a mental health organisation creates an organisation-wide plan for building the foundations of mental health and how to enhance psychological safety. METHODS: This review encompasses strategies across psychological safety and organisational culture change to increase psychological safety at an individual, team and organisational level. We set out a comprehensive overview of the types of strategies and interventions for increasing the ethos of psychological safety and setting the foundations for delivering an organisation-wide programme on this topic. We also provide a list of key targeted areas in mental health that would maximally benefit from increasing psychological safety-both in clinical and non-clinical settings. CONCLUSIONS: Psychological safety is a crucial determinant of safe and effective patient care in mental health services. This paper provides the key steps and considerations, creating a large-scale programme in psychological safety with a focus on mental health and drawing from the current literature, providing concrete steps for how our current understanding of psychological safety into practice.

2.
Proc Natl Acad Sci U S A ; 103(18): 6988-93, 2006 May 02.
Article in English | MEDLINE | ID: mdl-16627621

ABSTRACT

Histone acetylation affects many nuclear processes including transcription, chromatin assembly, and DNA damage repair. Acetylation of histone H3 lysine 56 (H3 K56ac) in budding yeast occurs during mitotic S phase and persists during DNA damage repair. Here, we show that H3 K56ac is also present during premeiotic S phase and is conserved in fission yeast. Furthermore, the H3 K56ac modification is not observed in the absence of the histone chaperone Asf1. asf1delta and H3 K56R mutants exhibit similar sensitivity to DNA damaging agents. Mutational analysis of Asf1 demonstrates that DNA damage sensitivity correlates with (i) decreased levels of H3 K56ac and (ii) a region implicated in histone binding. In contrast, multiple asf1 mutants that are resistant to DNA damage display WT levels of K56ac. These data suggest that maintenance of H3 K56 acetylation is a primary contribution of Asf1 to genome stability in yeast.


Subject(s)
Cell Cycle Proteins/metabolism , Histones/metabolism , Lysine/metabolism , Meiosis/physiology , Molecular Chaperones/metabolism , S Phase/physiology , Saccharomyces cerevisiae Proteins/metabolism , Acetylation , Cell Cycle Proteins/chemistry , Cell Cycle Proteins/genetics , DNA Damage , Models, Molecular , Molecular Chaperones/genetics , Phenotype , Protein Conformation , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/genetics , Spores, Fungal/metabolism
3.
Cell Mol Life Sci ; 60(2): 422-9, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12678505

ABSTRACT

CpG motifs originating from bacterial DNA (CpG DNA) can act as danger signals for the mammalian immune system. These CpG DNA motifs like many other pathogen-associated molecular patterns are believed to be recognized by a member of the toll-like receptor family, TLR-9. Here we show results suggesting that heat shock protein 90 (hsp90) is also implicated in the recognition of CpG DNA. Hsp90 was characterized as a binder to oligodeoxynucleotides (ODNs) containing CpG motifs (CpG ODNs) after several purification steps from crude protein extracts of peripheral blood mononuclear cells. This finding was further supported by direct binding of CpG ODNs to commercially available human hsp90. Additionally, immunohistochemistry studies showed redistribution of hsp90 upon CpG ODN uptake. Thus, we propose that hsp90 can act as a ligand transfer molecule and/or play a central role in the signaling cascade induced by CpG DNA.


Subject(s)
HSP90 Heat-Shock Proteins/metabolism , Oligodeoxyribonucleotides/metabolism , Signal Transduction , Cell Line , Chromatography, High Pressure Liquid , DNA-Binding Proteins/metabolism , Electrophoresis, Gel, Two-Dimensional , Electrophoretic Mobility Shift Assay , HSP90 Heat-Shock Proteins/chemistry , HSP90 Heat-Shock Proteins/isolation & purification , Humans , Jurkat Cells , Leukocytes, Mononuclear/chemistry , Nanotechnology , Receptors, Cell Surface/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Toll-Like Receptor 9 , U937 Cells
4.
J Exp Med ; 194(9): 1313-23, 2001 Nov 05.
Article in English | MEDLINE | ID: mdl-11696596

ABSTRACT

We eluted peptides from class I molecules of HLA-A2.1(+) breast adenocarcinoma and loaded reverse phase high-performance liquid chromatography (HPLC) fractions onto dendritic cells to prime naive CD8(+) T cells. Fractions that supported growth of tumor-specific cytotoxic T lymphocytes were analyzed by nano-HPLC micro-ESI tandem mass spectrometry. Six HLA-A2.1-binding peptides, four 9-mers (P1-P4) differing in the COOH-terminal residue, and two 10-mers (P5 and P6) with an additional COOH-terminal alanine, were identified in one fraction. Peptide sequences were homologous to cyclin B1. We primed CD8(+) T cells from another HLA-A2.1(+) healthy donor with synthetic peptides and generated P4-specific responses. We also detected memory T cells specific for one or more of these peptides in patients with breast cancer and squamous cell carcinomas of the head and neck (SCCHN). T cells from one patient, restimulated once in vitro, could kill the tumor cell line from which the peptides were derived. Immunohistochemical analysis of tumor lines and tissue sections showed cyclin B1 overexpression and aberrant localization in the cytoplasm instead of the nucleus. Sequencing genomic DNA and cDNA corresponding to P1-P6 region showed that differences in COOH-terminal residues were not due to either DNA mutations or errors in transcription, suggesting a high error rate in translation of cyclin B1 protein in tumors.


Subject(s)
Antigens, Neoplasm/immunology , Breast Neoplasms/immunology , CD8-Positive T-Lymphocytes/immunology , Carcinoma, Squamous Cell/immunology , Cyclin B/immunology , Head and Neck Neoplasms/immunology , Antigens, Neoplasm/genetics , Base Sequence , Breast Neoplasms/pathology , CD8-Positive T-Lymphocytes/cytology , Carcinoma, Squamous Cell/pathology , Cells, Cultured , Cyclin B/biosynthesis , Cyclin B/genetics , Cyclin B1 , DNA , DNA, Complementary , Female , Gene Expression , HLA-A2 Antigen/genetics , HLA-A2 Antigen/immunology , Head and Neck Neoplasms/pathology , Health Status , Humans , Immunologic Memory , Molecular Sequence Data , Mutagenesis , Peptides/genetics , Peptides/immunology , RNA , Tissue Donors , Tumor Cells, Cultured
5.
RNA ; 7(10): 1464-75, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11680851

ABSTRACT

In Escherichia coli, the exoribonuclease polynucleotide phosphorylase (PNPase), the endoribonuclease RNase E, a DEAD-RNA helicase and the glycolytic enzyme enolase are associated with a high molecular weight complex, the degradosome. This complex has an important role in processing and degradation of RNA. Chloroplasts contain an exoribonuclease homologous to E. coli PNPase. Size exclusion chromatography revealed that chloroplast PNPase elutes as a 580-600 kDa complex, suggesting that it can form an enzyme complex similar to the E. coli degradosome. Biochemical and mass-spectrometric analysis showed, however, that PNPase is the only protein associated with the 580-600 kDa complex. Similarly, a purified recombinant chloroplast PNPase also eluted as a 580-600 kDa complex after gel filtration chromatography. These results suggest that chloroplast PNPase exists as a homo-multimer complex. No other chloroplast proteins were found to associate with chloroplast PNPase during affinity chromatography. Database analysis of proteins homologous to E. coli RNase E revealed that chloroplast and cyanobacterial proteins lack the C-terminal domain of the E. coli protein that is involved in assembly of the degradosome. Together, our results suggest that PNPase does not form a degradosome-like complex in the chloroplast. Thus, RNA processing and degradation in this organelle differ in several respects from those in E. coli.


Subject(s)
Chloroplasts/enzymology , Endoribonucleases/metabolism , Escherichia coli/enzymology , Multienzyme Complexes/metabolism , Polyribonucleotide Nucleotidyltransferase/metabolism , RNA Helicases/metabolism , Chaperonin 60/chemistry , Chromatography, Affinity , Electrophoresis, Polyacrylamide Gel , Endoribonucleases/chemistry , Multienzyme Complexes/chemistry , Photosynthesis , Polyribonucleotide Nucleotidyltransferase/chemistry , RNA Helicases/chemistry , Spinacia oleracea
6.
Mol Cell ; 8(3): 505-15, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11583614

ABSTRACT

The pathway and complete collection of factors that orchestrate ribosome assembly are not clear. To address these problems, we affinity purified yeast preribosomal particles containing the nucleolar protein Nop7p and developed means to separate their components. Nop7p is associated primarily with 66S preribosomes containing either 27SB or 25.5S plus 7S pre-rRNAs. Copurifying proteins identified by mass spectrometry include ribosomal proteins, nonribosomal proteins previously implicated in 60S ribosome biogenesis, and proteins not known to be involved in ribosome production. Analysis of strains mutant for eight of these proteins not previously implicated in ribosome biogenesis showed that they do participate in this pathway. These results demonstrate that proteomic approaches in concert with genetic tools provide powerful means to purify and characterize ribosome assembly intermediates.


Subject(s)
Fungal Proteins/metabolism , Nuclear Proteins/metabolism , Ribosomes/chemistry , Saccharomyces cerevisiae/metabolism , Cell Fractionation , Chromatography, Affinity , Fungal Proteins/genetics , Fungal Proteins/isolation & purification , Genes, Reporter , Immunoblotting , Nuclear Proteins/chemistry , Nuclear Proteins/genetics , Nuclear Proteins/isolation & purification , RNA, Fungal/metabolism , RNA, Ribosomal/metabolism , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Ribosomes/metabolism
7.
J Immunol ; 167(6): 3223-30, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11544309

ABSTRACT

Human minor histocompatibility Ags (mHag) present significant barriers to successful bone marrow transplantation. However, the structure of human mHag and the basis for antigenic disparities are still largely unknown. Here we report the identification of the gene encoding the human mHag HA-2 as a previously unknown member of the class I myosin family, which we have designated MYO1G. The gene is located on the short arm of chromosome 7. Expression of this gene is limited to cells of hemopoietic origin, in keeping with the previously defined tissue expression of the HA-2 Ag. RT-PCR amplification of MYO1G from different individuals led to the identification of two genetic variants, designated MYO1G(V) and MYO1G(M). The former encodes the peptide sequence previously shown to be the HA-2 epitope (YIGEVLVSV), whereas the latter shows a single amino acid change in this peptide (YIGEVLVSM). This change has only a modest effect on peptide binding to the class I MHC-restricted element HLA-A*0201, and a minimal impact on recognition by T cells when added exogenously to target cells. Nonetheless, as detected using either T cells or mass spectrometry, this amino acid change results in a failure of the latter peptide to be presented at the surface of cells that express MYO1G(M) endogenously. These studies have thus identified a new mHag-encoding gene, and thereby provide additional information about both the genetic origins of human mHag as well as the underlying basis of an Ag-positive vs Ag-negative state.


Subject(s)
Chromosomes, Human, Pair 7/genetics , Genes , Minor Histocompatibility Antigens/genetics , Multigene Family , Myosins/genetics , Neoplasm Proteins/genetics , Alleles , Amino Acid Substitution , Antigen Presentation , Epitopes/genetics , Exons/genetics , Fourier Analysis , Genetic Variation , HLA-A Antigens/metabolism , Humans , In Situ Hybridization, Fluorescence , Lymphocytes/metabolism , Minor Histocompatibility Antigens/immunology , Myeloid Cells/metabolism , Myosins/immunology , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Amino Acid , T-Lymphocytes/immunology
8.
J Immunol ; 167(3): 1212-21, 2001 Aug 01.
Article in English | MEDLINE | ID: mdl-11466336

ABSTRACT

We have studied the contributions of proteasome inhibitor-sensitive and -insensitive proteases to the generation of class I MHC-associated peptides. The cell surface expression of 13 different human class I MHC alleles was inhibited by as much as 90% or as little as 40% when cells were incubated with saturating concentrations of three different proteasome inhibitors. Inhibitor-resistant class I MHC expression was not due to TAP-independent expression or preexisting internal stores of peptides. Furthermore, it did not correlate with the amount or specificity of residual proteasome activity as determined in in vitro proteolysis assays and was not augmented by simultaneous incubation with multiple inhibitors. Mass spectrometry was used to directly characterize the peptides expressed in the presence and absence of proteasome inhibitors. The number of peptide species detected correlated with the levels of class I detected by flow cytometry. Thus, for many alleles, a significant proportion of associated peptide species continue to be generated in the presence of saturating levels of proteasome inhibitors. Comparison of the peptide-binding motifs of inhibitor-sensitive and -resistant class I alleles further suggested that inhibitor-resistant proteolytic activities display a wide diversity of cleavage specificities, including a trypsin-like activity. Sequence analysis demonstrated that inhibitor-resistant peptides contain diverse carboxyl termini and are derived from protein substrates dispersed throughout the cell. The possible contributions of inhibitor-resistant proteasome activities and nonproteasomal proteases residing in the cytosol to the peptide profiles associated with many class I MHC alleles are discussed.


Subject(s)
Alleles , Cysteine Endopeptidases/metabolism , Cysteine Proteinase Inhibitors/pharmacology , HLA Antigens/biosynthesis , Histocompatibility Antigens Class I/biosynthesis , Multienzyme Complexes/antagonists & inhibitors , Multienzyme Complexes/metabolism , Peptide Fragments/biosynthesis , ATP Binding Cassette Transporter, Subfamily B, Member 2 , ATP-Binding Cassette Transporters/physiology , Cell Line, Transformed , Flow Cytometry , HLA Antigens/genetics , HLA Antigens/metabolism , HLA-A Antigens/biosynthesis , HLA-A1 Antigen/biosynthesis , HLA-A2 Antigen , HLA-B Antigens/biosynthesis , HLA-B51 Antigen , HLA-B8 Antigen/biosynthesis , Histocompatibility Antigens Class I/genetics , Histocompatibility Antigens Class I/metabolism , Humans , Mass Spectrometry , Peptide Fragments/genetics , Peptide Fragments/metabolism , Proteasome Endopeptidase Complex , Substrate Specificity/immunology , Transfection , Tumor Cells, Cultured
9.
Curr Biol ; 11(12): 996-1000, 2001 Jun 26.
Article in English | MEDLINE | ID: mdl-11448779

ABSTRACT

Posttranslational modifications of histone amino termini play an important role in modulating chromatin structure and function. Lysine methylation of histones has been well documented, and recently this modification has been linked to cellular processes involving gene transcription and heterochromatin assembly. However, the existence of arginine methylation on histones has remained unclear. Recent discoveries of protein arginine methyltransferases, CARM1 and PRMT1, as transcriptional coactivators for nuclear receptors suggest that histones may be physiological targets of these enzymes as part of a poorly defined transcriptional activation pathway. Here we show by using mass spectrometry that histone H4, isolated from asynchronously growing human 293T cells, is methylated at arginine 3 (Arg-3) in vivo. In support, a novel antibody directed against histone H4 methylated at Arg-3 independently demonstrates the in vivo occurrence of this modification and reveals that H4 Arg-3 methylation is highly conserved throughout eukaryotes. Finally, we show that PRMT1 is the major, if not exclusive, H4 Arg-3 methyltransfase in human 293T cells. These findings suggest a role for arginine methylation of histones in the transcription process.


Subject(s)
Histones/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Amino Acid Motifs , Animals , Arginine/metabolism , Cell Line , Genes, Reporter , Humans , Immunoblotting , Methylation , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism
10.
J Cell Biol ; 153(2): 251-62, 2001 Apr 16.
Article in English | MEDLINE | ID: mdl-11309407

ABSTRACT

The first step in the assembly of new chromatin is the cell cycle-regulated synthesis and nuclear import of core histones. The core histones include H2A and H2B, which are assembled into nucleosomes as heterodimers. We show here that the import of histone H2A and H2B is mediated by several members of the karyopherin (Kap; importin) family. An abundant complex of H2A, H2B, and Kap114p was detected in cytosol. In addition, two other Kaps, Kap121p and Kap123p, and the histone chaperone Nap1p were isolated with H2A and H2B. Nap1p is not necessary for the formation of the Kap114p-H2A/H2B complex or for import of H2A and H2B. We demonstrate that both histones contain a nuclear localization sequence (NLS) in the amino-terminal tail. Fusions of the NLSs to green fluorescent protein were specifically mislocalized to the cytoplasm in kap mutant strains. In addition, we detected a specific mislocalization in a kap95 temperature-sensitive strain, suggesting that this Kap is also involved in the import of H2A and H2B in vivo. Importantly, we show that Kap114p, Kap121p, and Kap95 interact directly with both histone NLSs and that RanGTP inhibits this association. These data suggest that the import of H2A and H2B is mediated by a network of Kaps, in which Kap114p may play the major role.


Subject(s)
Active Transport, Cell Nucleus/physiology , Cell Nucleus/metabolism , Histones/metabolism , Molecular Chaperones/metabolism , Nuclear Proteins/metabolism , Saccharomyces cerevisiae Proteins , Cell Cycle Proteins , Genes, Reporter , Histones/chemistry , Humans , Immunoblotting , Macromolecular Substances , Microscopy, Fluorescence , Nuclear Localization Signals , Nuclear Proteins/genetics , Nucleosome Assembly Protein 1 , Protein Binding , Proteins/metabolism , Recombinant Fusion Proteins/metabolism , Yeasts/genetics , Yeasts/metabolism , beta Karyopherins
11.
Clin Cancer Res ; 7(3 Suppl): 909s-916s, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11300491

ABSTRACT

The long-term survival of some patients with metastatic melanoma may be attributable in part to cellular immune responses to melanoma antigens. However, little is known about the level of CTL reactivity in vivo that is required for immunological control of tumor progression. In the present report, T-cell responses were evaluated with lymphocytes obtained from tumor-involved nodes and peripheral blood of a long-term melanoma survivor. Using an ELISPOT assay, naturally occurring functional T cells, which recognize the peptide ALLAVGATK (gp100(17-25)) plus two other HLA-A3 restricted peptides, were detected in a tumor-involved lymph node. The ALLAVGATK-reactive T cells were also evaluated by MHC-tetramers staining and were found to be CD8+ CD45RO+ L-selectin(-) CD11a+, suggesting that they are antigen experienced and have a memory phenotype. Unstimulated peripheral blood lymphocytes from the same patient demonstrated no detectable T-cell responses; however, a single stimulation with ALLAVGATK peptide in vitro resulted in a dramatic expansion of peptide-reactive CTLs. This patient, with evidence of tumor-reactive CTLs targeted to several tumor antigens in a tumor-involved lymph node and with evidence of a circulating memory T-cell response, has remained disease-free for 6 years, despite prior bulky nodal metastasis. In contrast, three HLA-A3+ patients with rapidly progressive metastatic melanoma had no detectable T-cell response in tumor-involved nodes or peripheral blood lymphocytes, even after peptide stimulation ex vivo. The presented data are consistent with a systemic polyvalent immune response against tumor in this long-term survivor. These data provide an estimate of the level of CTL response that may be associated with protection from tumor recurrence.


Subject(s)
Antigens, Neoplasm , Melanoma/immunology , CD11 Antigens/biosynthesis , CD8 Antigens/biosynthesis , CD8-Positive T-Lymphocytes/metabolism , Cell Line , Chromatography, High Pressure Liquid , Disease-Free Survival , HLA-A3 Antigen/metabolism , Humans , Immunohistochemistry , Immunologic Memory , Immunophenotyping , Interferon-gamma/biosynthesis , L-Selectin/biosynthesis , Leukocyte Common Antigens/biosynthesis , Lymphatic Metastasis , Lymphocytes/metabolism , Male , Melanoma/metabolism , Middle Aged , Peptides/chemistry , Phenotype , Time Factors
12.
Eur J Immunol ; 31(2): 421-32, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11180106

ABSTRACT

We studied the molecular basis for CD8 independence of in vivo generated (BM3.3) versus CD8 dependence of in vitro sensitized (KB5.C20/Des) alloreactive H-2K(b)-specific cytotoxic T lymphocytes (CTL). Using microcapillary high-performance liquid chromatography fractionation of H-2K(b) eluates, mass spectrometry and CTL reconstitution assays, we determined that BM3.3 and KB5.C20 recognize, respectively, a single peptide (pBM1) expressed on 8,000 H-2K(b) molecules per allogeneic cell, and three distinct peptides (pKB1, 2, 3), each expressed on around 200 H-2K(b) molecules per allogeneic cell. CD8 (in)dependence was intrinsic to the respective TCR/H-2K(b)-peptide interactions. KB5.C20 and BM3.3 TCR illustrate the correlation that appears to exist between CD8 dependence/low affinity and in vitro sensitization as opposed to low dependency on CD8 and high TCR affinity observed after in vivo sensitization. The results suggest that CD8-dependent alloreactive CTL obtained in vitro with high frequency correspond to low-affinity TCR from the MHC-biased TCR repertoire unpurged by negative selection and have implications for cellular immunotherapeutic approaches.


Subject(s)
CD8 Antigens/physiology , Peptides/immunology , T-Lymphocytes, Cytotoxic/immunology , Animals , Epitope Mapping , Mice , Mice, Inbred C57BL , Rats , Receptors, Antigen, T-Cell/metabolism
13.
Proc Natl Acad Sci U S A ; 98(4): 1763-8, 2001 Feb 13.
Article in English | MEDLINE | ID: mdl-11172025

ABSTRACT

T cell recognition of autoantigens is critical to progressive immune-mediated destruction of islet cells, which leads to autoimmune diabetes. We identified a naturally presented autoantigen from the human islet antigen glutamic acid decarboxylase, 65-kDa isoform (GAD65), by using a combination of chromatography and mass spectrometry of peptides bound by the type I diabetes (insulin-dependent diabetes mellitus, IDDM)-associated HLA-DR4 molecule. Peptides encompassing this epitope-stimulated GAD65-specific T cells from diabetic patients and a DR4-positive individual at high risk for developing IDDM. T cell responses were antagonized by altered peptide ligands containing single amino acid modifications. This direct identification and manipulation of GAD65 epitope recognition provides an approach toward dissection of the complex CD4(+) T cell response in IDDM.


Subject(s)
Antigen Presentation/immunology , Autoantigens/immunology , Diabetes Mellitus, Type 1/immunology , Epitopes, T-Lymphocyte/immunology , Glutamate Decarboxylase/immunology , Isoenzymes/immunology , Adolescent , Adult , Amino Acid Sequence , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , Cell Line , HLA-DR4 Antigen/immunology , Humans , Interferon-gamma/immunology , Interferon-gamma/pharmacology , Molecular Sequence Data
14.
J Exp Med ; 193(2): 195-206, 2001 Jan 15.
Article in English | MEDLINE | ID: mdl-11148223

ABSTRACT

Minor histocompatibility antigens (mHAgs) present a significant impediment to organ and bone marrow transplantation between HLA-identical donor and recipient pairs. Here we report the identification of a new HLA-A*0201-restricted mHAg, HA-8. Designation of this mHAg as HA-8 is based on the nomenclature of Goulmy (Goulmy, E. 1996. Curr. Opin. Immunol. 8:75-81). This peptide, RTLDKVLEV, is derived from KIAA0020, a gene of unknown function located on chromosome 9. Polymorphic alleles of KIAA0020 encode the alternative sequences PTLDKVLEV and PTLDKVLEL. Genotypic analysis demonstrated that the HA-8-specific cytotoxic T lymphocyte (CTL) clone SKH-13 recognized only cells that expressed the allele encoding R at P1. However, when PTLDKVLEV was pulsed onto cells, or when a minigene encoding this sequence was used to artificially translocate this peptide into the endoplasmic reticulum, it was recognized by CTLs nearly as well as RTLDKVLEV. This indicates that the failure of CTLs to recognize cells expressing the PTLDKVLEV-encoding allele of KIAA0020 is due to a failure of this peptide to be appropriately proteolyzed or transported. Consistent with the latter possibility, PTLDKVLEV and its longer precursors were transported poorly compared with RTLDKVLEV by transporter associated with antigen processing (TAP). These studies identify a new human mHAg and provide the first evidence that minor histocompatibility differences can result from the altered processing of potential antigens rather than differences in interaction with the relevant major histocompatibility complex molecule or T cell receptor.


Subject(s)
Antigen Presentation , Minor Histocompatibility Antigens/metabolism , Alleles , Amino Acid Sequence , Base Sequence , Clone Cells , DNA Primers/genetics , Epitopes/chemistry , Epitopes/genetics , Female , Humans , Male , Mass Spectrometry , Minor Histocompatibility Antigens/chemistry , Minor Histocompatibility Antigens/genetics , Molecular Sequence Data , Pedigree , Polymorphism, Genetic , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Amino Acid
15.
J Exp Med ; 192(12): 1755-62, 2000 Dec 18.
Article in English | MEDLINE | ID: mdl-11120772

ABSTRACT

Posttranslational modification of peptide antigens has been shown to alter the ability of T cells to recognize major histocompatibility complex (MHC) class I-restricted peptides. However, the existence and origin of naturally processed phosphorylated peptides presented by MHC class I molecules have not been explored. By using mass spectrometry, significant numbers of naturally processed phosphorylated peptides were detected in association with several human MHC class I molecules. In addition, CD8(+) T cells could be generated that specifically recognized a phosphorylated epitope. Thus, phosphorylated peptides are part of the repertoire of antigens available for recognition by T cells in vivo.


Subject(s)
Antigen Presentation , Histocompatibility Antigens Class I/immunology , Phosphopeptides/immunology , Phosphopeptides/metabolism , Alleles , Amino Acid Sequence , Animals , Antigens/chemistry , Antigens/immunology , Antigens/metabolism , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Cell Line , Cytokines/metabolism , Epitopes, T-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/immunology , Epitopes, T-Lymphocyte/metabolism , HLA Antigens/immunology , Humans , Interferon-gamma/biosynthesis , Mass Spectrometry , Mice , Mice, Inbred C57BL , Phosphopeptides/chemistry
16.
Science ; 290(5490): 337-41, 2000 Oct 13.
Article in English | MEDLINE | ID: mdl-11030652

ABSTRACT

A nuclear isoform of myosin I beta that contains a unique 16-amino acid amino-terminal extension has been identified. An affinity-purified antibody to the 16-amino acid peptide demonstrated nuclear staining. Confocal and electron microscopy revealed that nuclear myosin I beta colocalized with RNA polymerase II in an alpha-amanitin- and actinomycin D-sensitive manner. The antibody coimmunoprecipitated RNA polymerase II and blocked in vitro RNA synthesis. This isoform of myosin I beta appears to be in a complex with RNA polymerase II and may affect transcription.


Subject(s)
Cell Nucleus/metabolism , Molecular Motor Proteins , Myosins/metabolism , RNA Polymerase II/metabolism , RNA/biosynthesis , Transcription, Genetic , 3T3 Cells , Actins/metabolism , Amanitins/pharmacology , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Dactinomycin/pharmacology , Exons , HeLa Cells , Humans , Mice , Microscopy, Confocal , Microscopy, Electron , Molecular Sequence Data , Myosins/chemistry , Myosins/genetics , Myosins/immunology , Nucleic Acid Synthesis Inhibitors/pharmacology , Precipitin Tests , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/immunology , Protein Isoforms/metabolism
17.
Anal Chem ; 72(18): 4266-74, 2000 Sep 15.
Article in English | MEDLINE | ID: mdl-11008759

ABSTRACT

Subfemtomole peptide sequence analysis has been achieved using microcapillary HPLC columns, with integrated nanoelectrospray emitters, coupled directly to a Fourier transform ion cyclotron resonance mass spectrometer. Accurate mass (+/-0.010 Da) peptide maps are generated from a standard six-protein digest mixture, whose principle components span a concentration dynamic range of 1000:1. Iterative searches against approximately 189000 entries in the OWL database readily identify each protein, with high sequence coverage (20-60%), from as little as 10 amol loaded on-column. In addition, a simple variable-flow HPLC apparatus provides for on-line tandem mass spectrometric analysis of tryptic peptides at the 400-amol level. MS/MS data are searched against approximately 280000 entries in a nonredundant protein database using SEQUEST. Accurate precursor and product ion mass information readily identifies primary amino acid sequences differing by asparagine vs aspartic acid (deltam = 0.98 Da) and glutamine vs lysine (deltam = 0.036 Da).


Subject(s)
Peptides/analysis , Algorithms , Amino Acid Sequence , Animals , Chromatography, High Pressure Liquid , Cyclotrons , Fourier Analysis , Molecular Sequence Data , Muscle Proteins/chemistry , Peptide Mapping , Rabbits , Sequence Analysis , Spectrometry, Mass, Electrospray Ionization
18.
Mol Reprod Dev ; 57(2): 185-93, 2000 Oct.
Article in English | MEDLINE | ID: mdl-10984419

ABSTRACT

We have characterized the sperm nuclear basic proteins (SNBPs) of the sticklebacks in the suborder Gasterosteoidei. The complete amino acid sequence of the protamines from Aulorhynchus flavidus, Pungitius pungitius, Gasterosteus aculeatus, (anadromous) and G. wheatlandi, as well as the sequences of the protamines of several species pairs of freshwater G. aculeatus, have been determined. Analysis of the primary structure of these proteins has shown that: a) despite the relatively low amino acid complexity and small molecular mass of these basic proteins, they are very good molecular markers at the generic level. The bootstrap parsimony analysis using their sequences provides a phylogenetic relationship for the old anadromous species of Gasterosteoidei which is identical to that obtained from morphological and behavioral analysis; b) the comparison of the sequences also suggests that protamines from the suborder Gasterosteoidei have most likely evolved from a common gene in the early Acanthopterygii by an extension of the carboxy terminal portion of the molecule; c) protamines are not good markers for recent postglacial freshwater isolates of G. aculeatus. However, in the unique case of Enos Lake (British Columbia), we have been able to detect an additional minor protamine component in the benthic forms of G. aculeatus that is not present in the limnetic forms. Thus, this new protamine must have appeared during the past 12,000 years concomitantly with the speciation of benthics and limnetics in this lake.


Subject(s)
Evolution, Molecular , Fishes/genetics , Nuclear Proteins/genetics , Protamines/genetics , Spermatozoa/chemistry , Amino Acid Sequence , Animals , Fishes/metabolism , Genetic Markers , Male , Molecular Sequence Data , Nuclear Proteins/chemistry , Phosphorylation , Protamines/chemistry , Sequence Homology, Amino Acid
19.
Cell ; 102(3): 279-91, 2000 Aug 04.
Article in English | MEDLINE | ID: mdl-10975519

ABSTRACT

Phosphorylation of histone H3 at serine 10 occurs during mitosis and meiosis in a wide range of eukaryotes and has been shown to be required for proper chromosome transmission in Tetrahymena. Here we report that Ipl1/aurora kinase and its genetically interacting phosphatase, Glc7/PP1, are responsible for the balance of H3 phosphorylation during mitosis in Saccharomyces cerevisiae and Caenorhabditis elegans. In these models, both enzymes are required for H3 phosphorylation and chromosome segregation, although a causal link between the two processes has not been demonstrated. Deregulation of human aurora kinases has been implicated in oncogenesis as a consequence of chromosome missegregation. Our findings reveal an enzyme system that regulates chromosome dynamics and controls histone phosphorylation that is conserved among diverse eukaryotes.


Subject(s)
Caenorhabditis elegans/cytology , Fungal Proteins/metabolism , Histones/metabolism , Mitosis , Phosphoprotein Phosphatases/metabolism , Protein Serine-Threonine Kinases/metabolism , Saccharomyces cerevisiae/cytology , Animals , Aurora Kinases , Caenorhabditis elegans/metabolism , Genome , Helminth Proteins/metabolism , Phenotype , Phosphorylation , RNA, Antisense , RNA, Small Interfering , Saccharomyces cerevisiae/metabolism , Serine/metabolism , Species Specificity
20.
J Biol Chem ; 275(47): 36698-702, 2000 Nov 24.
Article in English | MEDLINE | ID: mdl-10978310

ABSTRACT

alpha-Hemolysin (HlyA) is a secreted protein virulence factor observed in certain uropathogenic strains of Escherichia coli. The active, mature form of HlyA is produced by posttranslational modification of the protoxin that is mediated by acyl carrier protein and an acyltransferase, HlyC. We have now shown using mass spectrometry that these modifications, when observed in protein isolated in vivo, consist of acylation at the epsilon-amino groups of two internal lysine residues, at positions 564 and 690, with saturated 14- (68%), 15- (26%), and 17- (6%) carbon amide-linked side chains. Thus, HlyA activated in vivo consists of a heterogeneous family of up to nine different covalent structures, and the substrate specificity of the HlyC acyltransferase appears to differ from that of the closely related CyaC acyltransferase expressed by Bordetella pertussis.


Subject(s)
Acyltransferases , Bacterial Proteins/metabolism , Bacterial Toxins/metabolism , Escherichia coli Proteins , Escherichia coli , Fatty Acids/metabolism , Hemolysin Proteins/metabolism , Acylation , Gas Chromatography-Mass Spectrometry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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