Research Interests: Biology, Cell Biology, Cell Signaling, Medicine, Biological Sciences, and 15 moreHSP, Cell line, Brain, Humans, Cell Death, Bcl, Heat Shock, Heat Shock Protein, Growth Factor, DNA binding proteins, Chaperone, Adenosine Triphosphate, Growth factor receptor, Immunoblotting, and Medical and Health Sciences
Research Interests:
Research Interests:
Heat shock factor 1 (HSF1) is the ubiquitous stress-responsive transcriptional activator which is essential for the inducible transcription of genes encoding heat shock proteins and molecular chaperones. HSF1 localizes within the nucleus... more
Heat shock factor 1 (HSF1) is the ubiquitous stress-responsive transcriptional activator which is essential for the inducible transcription of genes encoding heat shock proteins and molecular chaperones. HSF1 localizes within the nucleus of cells exposed to heat shock, heavy metals, and amino acid analogues, to form large, irregularly shaped, brightly staining granules which are not detected during attenuation of the heat shock response or when cells are returned to their normal growth conditions. The kinetics of detection of HSF1 granules parallels the transient induction of heat shock gene transcription. HSF1 granules are also detected using an HSF1-Flag epitope tagged protein or a chimeric HSF1-green fluorescent protein which reveals that these nuclear structures are stress-induced and can be detected in living cells. The spatial organization of HSF1 granules in nuclei of stressed cells reveals that they are novel nuclear structures which are stress-dependent and provides evidenc...
Research Interests:
Research Interests:
The cell nucleus is organized as discrete domains, often associated with specific events involved in chromosome organization, replication, and gene expression. We have examined the spatial and functional relationship between the sites of... more
The cell nucleus is organized as discrete domains, often associated with specific events involved in chromosome organization, replication, and gene expression. We have examined the spatial and functional relationship between the sites of heat shock gene transcription and the speckles enriched in splicing factors in primary human fibroblasts by combining immunofluorescence and fluorescence in situ hybridization (FISH). The hsp90α and hsp70 genes are inducibly regulated by exposure to stress from a low basal level to a high rate of transcription; additionally the hsp90α gene contains 10 introns whereas the hsp70 gene is intronless. At 37°C, only 30% of hsp90α transcription sites are associated with speckles whereas little association is detected with the hsp70 gene, whose constitutive expression is undetectable relative to the hsp90α gene. Upon exposure of cells to heat shock, the heavy metal cadmium, or the amino acid analogue azetidine, transcription at the hsp90α and hsp70 gene loc...
Research Interests: Genetics, Biology, Cell Biology, Medicine, Biological Sciences, and 15 moreHumans, Nuclear Structure, Heavy Metal, Alternative splicing, Cadmium, Introns, Fluorescent Antibody Technique, Fluorescent in situ hybridization, Heat Shock, Intron, Alternative Splicing, Ribonucleoproteins, Exon, fibroblasts, and Medical and Health Sciences
Vertebrate cells express a family of heat shock transcription factors (HSF1 to HSF4) that coordinate the inducible regulation of heat shock genes in response to diverse signals. HSF1 is potent and activated rapidly though transiently by... more
Vertebrate cells express a family of heat shock transcription factors (HSF1 to HSF4) that coordinate the inducible regulation of heat shock genes in response to diverse signals. HSF1 is potent and activated rapidly though transiently by heat shock, whereas HSF2 is a less active transcriptional regulator but can retain its DNA binding properties for extended periods. Consequently, the differential activation of HSF1 and HSF2 by various stresses may be critical for cells to survive repeated and diverse stress challenges and to provide a mechanism for more precise regulation of heat shock gene expression. Here we show, using a novel DNA binding and detection assay, that HSF1 and HSF2 are coactivated to different levels in response to a range of conditions that cause cell stress. Above a low basal activity of both HSFs, heat shock preferentially activates HSF1, whereas the amino acid analogue azetidine or the proteasome inhibitor MG132 coactivates both HSFs to different levels and hemin...
Research Interests: Cellular Biology, Fluorescence Microscopy, Biology, Gene expression, Heat Shock Transcription Factor, and 15 moreBiological Sciences, DNA, Animals, Cell nucleus, DNA binding, Environmental Stress, Heat Shock, Amino Acid Profile, Heat Shock Proteins, Heat Shock Protein, Cytoplasm, DNA binding proteins, Adverse effect, heat shock factor, and Medical and Health Sciences
Research Interests: Chemistry, Calcium, Medicine, Biological Sciences, Crystal structure, and 15 moreHSP, Humans, ATPase, Animals, CHEMICAL SCIENCES, Cattle, High Resolution, Active site, Phosphates, Heat Shock Protein, Binding Site, Adenosine Triphosphate, Adenosine Diphosphate, Molecular Sequence Data, and binding sites
The EMBO Journal encourages and publishes articles that report novel findings of wide biological significance in the areas of development, immunology, neuroscience, plant biology, structural biology, genomic & computational biology,... more
The EMBO Journal encourages and publishes articles that report novel findings of wide biological significance in the areas of development, immunology, neuroscience, plant biology, structural biology, genomic & computational biology, genome stability & dynamics, chromatin & ...
Research Interests: Cell Signaling, Biological Sciences, HSP, Cell line, Brain, and 15 moreHumans, Cell Death, Peptides, Bcl, Heat Shock, Protein Conformation, Growth Factor, Protein Binding, Protein Denaturation, DNA binding proteins, Chaperone, Adenosine Triphosphate, Growth factor receptor, Immunoblotting, and Medical and Health Sciences
Summary Heat shock proteins interact with multiple key components of signaling pathways that regulate growth and development. The molecular relationships between heat shock proteins, various signaling proteins and partner proteins appear... more
Summary Heat shock proteins interact with multiple key components of signaling pathways that regulate growth and development. The molecular relationships between heat shock proteins, various signaling proteins and partner proteins appear to be critical for the ...
Research Interests:
Protein misfolding and the formation of aggregates are increasingly recognized components of the pathology of human genetic disease and hallmarks of many neurodegenerative disorders. As exemplified by polyglutamine diseases, the... more
Protein misfolding and the formation of aggregates are increasingly recognized components of the pathology of human genetic disease and hallmarks of many neurodegenerative disorders. As exemplified by polyglutamine diseases, the propensity ...
Research Interests:
In Caenorhabditis elegans, the programmed repression of the heat shock response (HSR) accompanies the transition to reproductive maturity, leaving cells vulnerable to environmental stress and protein aggregation with age. To identify the... more
In Caenorhabditis elegans, the programmed repression of the heat shock response (HSR) accompanies the transition to reproductive maturity, leaving cells vulnerable to environmental stress and protein aggregation with age. To identify the factors driving this event, we performed an unbiased genetic screen for suppressors of stress resistance and identified the mitochondrial electron transport chain (ETC) as a central regulator of the age-related decline of the HSR and cytosolic proteostasis. Mild downregulation of ETC activity, either by genetic modulation or exposure to mitochondria-targeted xenobiotics, maintained the HSR in adulthood by increasing HSF-1 binding and RNA polymerase II recruitment at HSF-1 target genes. This resulted in a robust restoration of cytoplasmic proteostasis and increased vitality later in life, without detrimental effects on fecundity. We propose that low levels of mitochondrial stress regulate cytoplasmic proteostasis and healthspan during aging by coordi...
Protein aggregates are the hallmark of stressed and ageing cells, and characterize several pathophysiological states. Healthy metazoan cells effectively eliminate intracellular protein aggregates, indicating that efficient disaggregation... more
Protein aggregates are the hallmark of stressed and ageing cells, and characterize several pathophysiological states. Healthy metazoan cells effectively eliminate intracellular protein aggregates, indicating that efficient disaggregation and/or degradation mechanisms exist. However, metazoans lack the key heat-shock protein disaggregase HSP100 of non-metazoan HSP70-dependent protein disaggregation systems, and the human HSP70 system alone, even with the crucial HSP110 nucleotide exchange factor, has poor disaggregation activity in vitro. This unresolved conundrum is central to protein quality control biology. Here we show that synergic cooperation between complexed J-protein co-chaperones of classes A and B unleashes highly efficient protein disaggregation activity in human and nematode HSP70 systems. Metazoan mixed-class J-protein complexes are transient, involve complementary charged regions conserved in the J-domains and carboxy-terminal domains of each J-protein class, and are f...
Research Interests:
Research Interests:
Research Interests: Transcription Factors, In Situ Hybridization, Biological Sciences, Molecular and cellular biology, Sequence alignment, and 13 moreAnimals, Genes, Molecular cloning, Chickens, Age Factors, Heat Shock Proteins, Amino Acid Sequence, Base Sequence, DNA binding proteins, Gene Expression Regulation, Molecular Sequence Data, Restriction Mapping, and Medical and Health Sciences
Research Interests:
Heatshocktranscriptionfactors(HSFs)mediatetheinducibletranscriptionalresponseofgenesthatencode heat shock proteins and molecular chaperones. In vertebrates, three relatedHSFgenes (HSF1to -3) and the respective gene products (HSFs) have... more
Heatshocktranscriptionfactors(HSFs)mediatetheinducibletranscriptionalresponseofgenesthatencode heat shock proteins and molecular chaperones. In vertebrates, three relatedHSFgenes (HSF1to -3) and the respective gene products (HSFs) have been characterized. We report the cloning and characterization of human HSF4 (hHSF4), a novel member of the hHSF family that shares properties with other members of the HSF family yet appears to be functionally distinct. hHSF4 lacks the carboxyl-terminal hydrophobic
Research Interests: Common Property, Heat Shock Transcription Factor, Biological Sciences, Humans, Tomato, and 15 moreGenes, Cell nucleus, Skeletal Muscle, HeLa cells, DNA binding, Heat Shock, Heat Shock Protein, Amino Acid Sequence, Base Sequence, DNA binding proteins, Gene Expression Regulation, Tissue Specificity, Molecular Sequence Data, heat shock factor, and Medical and Health Sciences
Research Interests:
Research Interests:
Research Interests: Transcription Factors, Gene expression, Biological Sciences, Cell line, Stress response, and 12 moreAnimals, Male, Chickens, Gene Targeting, Heat Shock, Heat Shock Proteins, Transfection, Protein Conformation, B Lymphocytes, DNA binding proteins, Gene Expression Regulation, and Medical and Health Sciences
Research Interests:
Accumulation of aggregation-prone misfolded proteins disrupts normal cellular function and promotes ageing and disease. Bacteria, fungi and plants counteract this by solubilizing and refolding aggregated proteins via a powerful cytosolic... more
Accumulation of aggregation-prone misfolded proteins disrupts normal cellular function and promotes ageing and disease. Bacteria, fungi and plants counteract this by solubilizing and refolding aggregated proteins via a powerful cytosolic ATP-dependent bichaperone system, comprising the AAA+ disaggregase Hsp100 and the Hsp70-Hsp40 system. Metazoa, however, lack Hsp100 disaggregases. We show that instead the Hsp110 member of the Hsp70 superfamily remodels the human Hsp70-Hsp40 system to efficiently disaggregate and refold aggregates of heat and chemically denatured proteins in vitro and in cell extracts. This Hsp110 effect relies on nucleotide exchange, not on ATPase activity, implying ATP-driven chaperoning is not required. Knock-down of nematode Caenorhabditis elegans Hsp110, but not an unrelated nucleotide exchange factor, compromises dissolution of heat-induced protein aggregates and severely shortens lifespan after heat shock. We conclude that in metazoa, Hsp70-Hsp40 powered by Hsp110 nucleotide exchange represents the crucial disaggregation machinery that reestablishes protein homeostasis to counteract protein unfolding stress.
Research Interests:
Research Interests:
Research Interests:
The long-term health of the cell is inextricably linked to protein quality control. Under optimal conditions this is accomplished by protein homeostasis, a highly complex network of molecular interactions that balances protein... more
The long-term health of the cell is inextricably linked to protein quality control. Under optimal conditions this is accomplished by protein homeostasis, a highly complex network of molecular interactions that balances protein biosynthesis, folding, translocation, assembly/disassembly, and clearance. This review will examine the consequences of an imbalance in homeostasis on the flux of misfolded proteins that, if unattended, can result in severe molecular damage to the cell. Adaptation and survival requires the ability to sense damaged proteins and to coordinate the activities of protective stress response pathways and chaperone networks. Yet, despite the abundance and apparent capacity of chaperones and other components of homeostasis to restore folding equilibrium, the cell appears poorly adapted for chronic proteotoxic stress when conformationally challenged aggregation-prone proteins are expressed in cancer, metabolic disease, and neurodegenerative disease. The decline in biosy...
Research Interests:
The human HSP70 gene was modified in vitro using oligonucleotide-directed mutagenesis to add sequences encoding a peptide from the testis-specific form of human lactate dehydrogenase (LDH) to the carboxy terminus of HSP70. The... more
The human HSP70 gene was modified in vitro using oligonucleotide-directed mutagenesis to add sequences encoding a peptide from the testis-specific form of human lactate dehydrogenase (LDH) to the carboxy terminus of HSP70. The peptide-tagged ...
Research Interests: Biological Sciences, Cell line, Humans, Mutation, Animals, and 12 moreGenes, Fluorescent Antibody Technique, HeLa cells, Heat Shock Proteins, Transfection, Molecular weight, Protein Biosynthesis, Adenosine Triphosphate, binding sites, Mutation analysis, Chromosome deletion, and Medical and Health Sciences
1 Department of Molecular Biosciences, Rice Institute for Biomedical Research, Northwestern University, Evanston, Illinois, United States of America, 2 Faculty of Sciences, Centre for Biodiversity, Functional and Integrative Genomics... more
1 Department of Molecular Biosciences, Rice Institute for Biomedical Research, Northwestern University, Evanston, Illinois, United States of America, 2 Faculty of Sciences, Centre for Biodiversity, Functional and Integrative Genomics (BioFIG), University of Lisboa ...
Research Interests: Genetics, Caenorhabditis elegans, Protein Folding, Biology, Transcription Factors, and 15 moreMedicine, Gene expression, Molecular chaperones, RNA interference, Humans, Genetic Testing, Stress response, Animals, Protein Aggregation, Peptides, Superoxide Dismutase, Protein Expression, PLoS Genetics, Protein Conformation, and Gene Expression Regulation
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Transcriptional regulation of the human hsp70 gene in response to heat shock and other forms of physiological stress occurs through the activation of heat shock transcription factor (HSF). Exposure of cells to a heat shock temperature of... more
Transcriptional regulation of the human hsp70 gene in response to heat shock and other forms of physiological stress occurs through the activation of heat shock transcription factor (HSF). Exposure of cells to a heat shock temperature of 42 degrees C results in ...
Research Interests: Transcription Factors, Gene expression, Biological Sciences, Humans, Transcription Factor, and 12 moreGenes, Molecular cloning, Homeostasis, HeLa cells, Heat Shock, Heat Shock Protein, Recombinant Proteins, DNA binding proteins, Gene Expression Regulation, Adenosine Triphosphate, Psychology and Cognitive Sciences, and Medical and Health Sciences
Research Interests:
Research Interests: Biology, Transcription Factors, Gene expression, Western blotting, In Situ Hybridization, and 15 moreBiological Sciences, DNA, Spermatogenesis, Mice, Animals, Male, tESTIS, Heat Shock Proteins, Heat Shock Protein, Base Sequence, Gene Expression Regulation, Biology Reproduction, Molecular Sequence Data, heat shock factor, and Medical and Health Sciences
MOLECULAR AND CELLULAR BIOLOGY, Mar. 1993, p. 1392-1407 0270-7306/93/031392-16 $02.00/0 Copyright ©) 1993, American Society for Microbiology ... Activation of Heat Shock Gene Transcription by Heat Shock ... KEVIN D. SARGE, SHAWN P.... more
MOLECULAR AND CELLULAR BIOLOGY, Mar. 1993, p. 1392-1407 0270-7306/93/031392-16 $02.00/0 Copyright ©) 1993, American Society for Microbiology ... Activation of Heat Shock Gene Transcription by Heat Shock ... KEVIN D. SARGE, SHAWN P. MURPHY, AND RICHARD ...
Research Interests: Transcription Factors, Biological Sciences, Molecular and cellular biology, Humans, Escherichia coli, and 15 moreMice, Animals, Phosphorylation, T cells, Cell nucleus, Fluorescent Antibody Technique, Heat Shock Proteins, Transfection, Protein Conformation, Base Sequence, Cytoplasm, DNA binding proteins, Gene Expression Regulation, Molecular Sequence Data, and Medical and Health Sciences
Studies of the mutant gene in Huntington's disease, and for eight related neurodegenerative disorders, have identified polyglutamine (polyQ) expansions as a basis for cellular toxicity. This finding has led to a disease hypothesis... more
Studies of the mutant gene in Huntington's disease, and for eight related neurodegenerative disorders, have identified polyglutamine (polyQ) expansions as a basis for cellular toxicity. This finding has led to a disease hypothesis that protein aggregation and cellular dysfunction ...
Research Interests:
Research Interests:
In this paper, we show that upon heat shock, HSF1 concentrates in the nucleus of diploid human fibroblasts in two large foci. The relative distribution of HSF1 nuclear foci and active heat shock protein (hsp) genes was investigated by... more
In this paper, we show that upon heat shock, HSF1 concentrates in the nucleus of diploid human fibroblasts in two large foci. The relative distribution of HSF1 nuclear foci and active heat shock protein (hsp) genes was investigated by combining fluorescence in situ hybridization (FISH) for the detection of hsp nuclear transcripts and immunofluorescence for the detection of HSF1. We show that the HSF1 foci are distinct from the sites of hsp70 and hsp90 genes transcription. This is the second report of ploidy-dependent foci of transcription factors that are independent of their specific transcription sites. However, the correlation between the number of HSF1 foci and the ploidy of the cells strongly supports the existence of a specific chromosomal target for HSF1 foci.
Research Interests:
(1) We have derived a fine-structure map of the 70 kb mitochondrial genome of the yeast S. cerevisiae, strain D273-10B, and compared it with our previous maps for strain MH41-7B. Restriction fragment maps for 56 enzyme recognition sites... more
(1) We have derived a fine-structure map of the 70 kb mitochondrial genome of the yeast S. cerevisiae, strain D273-10B, and compared it with our previous maps for strain MH41-7B. Restriction fragment maps for 56 enzyme recognition sites for 13 endonucleases, Eco RI, Hpa I, Bam HI, Hha I, Hinc II, Xba I, Hind III, Bgl II, Pvu II, Sal I, Pst I, Sst I, and Xho I, have been derived. We have used several methods to obtain these maps: (a) Four enzymes (Sal I, Sst I, Xho I, Pst I), each of which cuts D273-10B mtDNA at a single site, were employed to localize and orient fragments from multi-site enzyme digests that are cleaved by the single-site enzyme. (b) Radioactively labeled probes (rRNA or copy RNA [cRNA] transcribed from simple-sequence petite mtDNA) were hybridized to restriction fragments from different digests for identification of fragments which share common sequences. (c) The products of double or triple enzyme digests were identified for mapping and confirmation of the localization of restriction sites. (2) The antibiotic-resistant (antR) loci for erythromycin (E), chloramphenicol (C), paromomycin (P), and oligomycin (OI, OII) were positioned on the physical restriction map by hybridization of 3H-labeled cRNA transcribed from simple-sequence petite mtDNAs that retain a single genetic antR marker to appropriate restriction fragments bound to nitrocellulose filters. (3) Mitochondrial transcripts (21s rRNA, 14s rRNA, and tRNAs) labeled with 125I were hybridized to restriction fragments for identification of the corresponding coding sequence. (4) The gene order and localization of the antR loci and mitochondrial transcripts are as follows: C(0-1.5u)-tRNA I(0-21.5u)-P(29-36.6u)-tRNA II(29-46.4u)-14s rRNA(36-38.3u)-OII(60.3-62.5u) - tRNA III(73-76u) - OI(78.6-83.0u) - tRNA IV(82.5-83.0u) - E(94.2-98.6u) - 21s rRNA (94.2-99.4u). (5) The DNA fine structure and gene map of the 70 kb D273-10B mtDNA were compared to the map of the larger MH41-7B (76 kb) mtDNA. There are 56 restriction sites on D273-10B and 67 sites on MH41-7B for the 13 enzymes studied. The additional restriction sites are largely accounted for by the presence, in MH41-7B, of two sets of sequences, "A" (2.7 kb) and "B" (3.0 kb), located on either side of the OII marker. The remainder of the fragments map is remarkably similar for the two strains. The distances separating the antR loci and the mitochondrial transcripts are very similar except in the two regions surrounding OII.
Research Interests: Genetics, RNA, Antibiotic Resistance, Saccharomyces cerevisiae, Gene Mapping, and 9 moreMitochondrial DNA, Nucleic acid hybridization, Microbial genetic and drug resistance, Mitochondrial Genome, Genetic linkage analysis, Genes, Fine Structure Constant, Species Specificity, and DNA Restriction Enzymes
The following topics are discussed: characterization of mtDNA transcripts including tRNA and messenger RNA; determination of the fraction of yeast mtDNA transcribed in vivo using mitochondrial RNA-DNA hybridization; analysis of... more
The following topics are discussed: characterization of mtDNA transcripts including tRNA and messenger RNA; determination of the fraction of yeast mtDNA transcribed in vivo using mitochondrial RNA-DNA hybridization; analysis of hybridization with single strand-specific Neurospora DNA-ase; effect of pre-annealing of RNA on mitochondrial RNA-DNA hybridization; chromatography of mitochondrial cysteinyl tRNA; stimulation of ³H-leucine incorporation into an Escherichia coli cell-free system
Research Interests: Genetics, Electron Microscopy, renewable Energy sources, Mitochondrial DNA, Escherichia coli, and 14 moreBeta decay, DNA hybridization, Genetic Map, Cytochrome oxidase, Mitochondrial Genome, Enzyme, Hydrogen isotopes, Amino Acid Sequence, Energy Source, Organic Compound, Organic Acid, Molecular Structure, Nucleic Acid, and single stranded DNA
Research Interests: Protein Folding, Apoptosis, Signal Transduction, Molecular chaperones, Humans, and 13 moreAnimals, Oncogene, Cell Death, Mitogen Activated Protein Kinase, Protein Function, Clinical Sciences, Spectrum, Neoplasms, Heat Shock Proteins, Protein Conformation, Heat Shock Protein, Cell Proliferation, and Mitogen- Activated Protein Kinases
Research Interests:
The folded state of proteins can be affected by many factors; these include alterations in the cellular environment and protein folding machinery. Also, the presence of misfolded proteins has been linked to several human pathologies. One... more
The folded state of proteins can be affected by many factors; these include alterations in the cellular environment and protein folding machinery. Also, the presence of misfolded proteins has been linked to several human pathologies. One class of these ...
Research Interests:
Research Interests:
Research Interests:
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Aug. 1990, p. 2441-2452 0099-2240/90/082441-12$02.00/0 Copyright C) 1990, American Society for Microbiology ... Restriction Enzyme Analysis of Mitochondrial DNA of the ... Aspergillus flavus group:... more
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Aug. 1990, p. 2441-2452 0099-2240/90/082441-12$02.00/0 Copyright C) 1990, American Society for Microbiology ... Restriction Enzyme Analysis of Mitochondrial DNA of the ... Aspergillus flavus group: A. ...