A5023324300- Heat shock proteins research
- Fungal and yeast genetics research
- Protein Structure and Dynamics
- Endoplasmic Reticulum Stress and Disease
- Enzyme Structure and Function
- thermodynamics and calorimetric analyses
- Genetics, Aging, and Longevity in Model Organisms
- Viral Infectious Diseases and Gene Expression in Insects
- Computational Drug Discovery Methods
- Plant biochemistry and biosynthesis
- DNA Repair Mechanisms
- ATP Synthase and ATPases Research
- Ubiquitin and proteasome pathways
- Toxin Mechanisms and Immunotoxins
- Cancer-related Molecular Pathways
- RNA Research and Splicing
- Microtubule and mitosis dynamics
- Cellular transport and secretion
- Melanoma and MAPK Pathways
- Telomeres, Telomerase, and Senescence
- Physiological and biochemical adaptations
- Carcinogens and Genotoxicity Assessment
- Cellular Mechanics and Interactions
- interferon and immune responses
- Insect and Pesticide Research
University of North Carolina at Charlotte
2016-2025
John Innes Centre
2019-2024
University of Chicago
2010-2015
University of Sheffield
2004-2011
Johns Hopkins University
2008-2010
Hôtel-Dieu de Québec
2010
Université Laval
2010
Cancer Research Center
2010
Boston University
2010
Institute of Cancer Research
2006
Activation of protein kinase clients by the Hsp90 system is mediated cochaperone Cdc37. Cdc37 requires phosphorylation at Ser13, but little known about regulation this essential posttranslational modification. We show that Ser13 uncomplexed phosphorylated in vivo, as well binary complex with a (C-K), or ternary and (H-C-K). Whereas pSer13-Cdc37 H-C-K resistant to nonspecific phosphatases, it efficiently dephosphorylated chaperone-targeted phosphatase 5 (PP5/Ppt1), which does not affect...
ABSTRACT The Hsp90 chaperone cycle catalyzes the final activation step of several important eukaryotic proteins (Hsp90 “clients”). Although largely a functional form Hsp90, an Hsp90-Gal4p DNA binding domain fusion (Hsp90-BD) displays no strong interactions in yeast two-hybrid system, consistent with general transience most Hsp90-client associations. Strong vivo are though detected when E33A mutation is introduced into this bait, that should arrest complexes at stage where client stabilized,...
SummaryIn budding yeast, the essential functions of Hsp70 chaperones Ssa1–4 are regulated through expression level, isoform specificity, and cochaperone activity. Suggesting a novel regulatory paradigm, we find that phosphorylation Ssa1 T36 within cyclin-dependent kinase (CDK) consensus site conserved among proteins alters client interactions. triggers displacement Ydj1, allowing to bind G1 cyclin Cln3 promote its degradation. The stress CDK Pho85 phosphorylates upon nitrogen starvation or...
The cell wall integrity mitogen-activated protein kinase (MAPK) cascade of Saccharomyces cerevisiae drives changes in gene expression response to stress. We show that the MAPK this pathway (Mpk1) and its pseudokinase paralog (Mlp1) use a noncatalytic mechanism activate transcription FKS2 gene. Transcriptional activation was dependent on Swi4/Swi6 (SBF) factor an activating signal Mpk1 but not activity. Activated (phosphorylated) Mlp1 were detected complex with Swi4 Swi6 at promoter....
The molecular chaperone Hsp90 protects deregulated signaling proteins that are vital for tumor growth and survival. Tumors generally display sensitivity selectivity toward inhibitors; however, the mechanism underlying this phenotype remains undefined. We report mitotic checkpoint kinase Mps1 phosphorylates a conserved threonine residue in amino-domain of Hsp90. This, turn, regulates function by reducing ATPase activity while fostering association with clients, including Mps1. Phosphorylation...
Hsp70 interactions are critical for cellular viability and the response to stress. Previous attempts characterize have been limited by their transient nature inability of current technologies distinguish direct versus bridged interactions. We report novel use cross-linking mass spectrometry (XL-MS) comprehensively Saccharomyces cerevisiae (budding yeast) protein interactome. Using this approach, we gained fundamental new insights into function, including definitive evidence self-association...
Heat shock protein 90 (Hsp90) is a molecular chaperone required for the activity of many most important regulatory proteins eukaryotic cells (the Hsp90 ‘clients’). Vertebrates have two isoforms cytosolic Hsp90, Hsp90α and Hsp90β. Hsp90β expressed constitutively to high level in tissues generally more abundant than Hsp90α, whereas stress‐inducible overexpressed cancerous cells. Expressed as sole yeast, human are both able provide essential functions. Activations certain clients (heat...
The yeast SBF transcription factor is a heterodimer comprised of Swi4 and Swi6 that has well defined role in cell cycle-specific transcription. serves second function the transcriptional response to wall stress which activated Mpk1 mitogen-activated protein kinase integrity signaling pathway forms complex with Swi4, DNA binding subunit SBF, conferring upon ability bind activate FKS2. Although Mpk1–Swi4 formation activation FKS2 does not require catalytic activity, phosphorylated by must be...
The serine/threonine protein phosphatase 5 (PP5) regulates multiple cellular signaling networks. A number of factors, including heat shock 90 (Hsp90), promote the activation PP5. However, it is unclear whether post-translational modifications also influence PP5 activity. Here, we show an "on/off switch" mechanism for regulation. casein kinase 1δ (CK1δ) phosphorylates T362 in catalytic domain PP5, which activates and enhances activity independent Hsp90. Overexpression phosphomimetic T362E-PP5...
ABSTRACT ERK5 is a mitogen-activated protein (MAP) kinase regulated in human cells by diverse mitogens and stresses but also suspected of mediating the effects number oncogenes. Its expression slt2 Δ Saccharomyces cerevisiae mutant rescued several phenotypes caused lack Slt2p (Mpk1p) cell integrity MAP kinase. able to provide this function yeast, as it activated signaling cascade that normally activates and, its active form, stimulate at least one key target (Rlm1p, major transcriptional...
The Mpk1 mitogen-activated protein kinase (MAPK) of the cell wall integrity signaling pathway uses a noncatalytic mechanism to activate SBF (Swi4/Swi6) transcription factor. Active forms complex with Swi4, DNA-binding subunit SBF, conferring ability bind DNA. Because activation is independent catalytic activity but requires be in an active conformation, we sought understand how interacts Swi4. Mutational analysis revealed that binding and Swi4 by intact D-motif-binding site, docking surface...
ABSTRACT Yeast is rendered temperature sensitive with loss of the C-terminal (CT) domain heat shock transcription factor (Hsf1). This was found to abrogate stimulation Slt2 (Mpk1), mitogen-activated protein kinase that directs reinforced cell integrity gene expression needed for high-temperature growth. In Hsf1 CT domain-deficient cells, still undergoes Mkk1/2-directed dual-Thr/Tyr phosphorylation in response pathway signaling, but low Hsp90 level suppresses any corresponding increase...
The activity of the Hsp70 molecular chaperone is regulated by a suite helper co-chaperones that include J-proteins. Studies on J-proteins have historically focused their expression, localization, and activation Hsp70. There growing evidence post-translational modifications (PTMs) chaperones (the code) fine-tune function. This mini-review summarizes current understanding role regulation PTMs major Ydj1 DNAJA1. Understanding these may provide novel therapeutic avenues for targeting in cancer...
Hsp70 is a well-conserved molecular chaperone involved in the folding, stabilization, and eventual degradation of many "client" proteins. regulated by suite co-chaperone molecules that assist Hsp70-client interaction stimulate intrinsic ATPase activity Hsp70. While previous studies have shown anticancer target ribonucleotide reductase (RNR) client Hsp70, regulatory co-chaperones remain to be determined. To identify co-chaperone(s) RNR activity, 28 yeast knockout mutants were screened for...
Abstract Heat shock protein 70 (Hsp70) is an important molecular chaperone that regulates oncoprotein stability and tumorigenesis. However, attempts to develop anti-chaperone drugs targeting molecules such as Hsp70 have been hampered by toxicity issues. regulated a suite of co-chaperone bring “clients” the primary for efficient folding. Rather than itself, here we examined feasibility inhibiting DNAJA1 novel anticancer strategy. We found be upregulated in variety cancers, suggesting role...