HSP42/YDR171W Summary Help

Standard Name HSP42 1
Systematic Name YDR171W
Feature Type ORF, Verified
Description Small heat shock protein (sHSP) with chaperone activity; forms barrel-shaped oligomers that suppress unfolded protein aggregation; involved in cytoskeleton reorganization after heat shock; protein abundance increases and forms cytoplasmic foci in response to DNA replication stress (1, 2, 3, 4, 5 and see Summary Paragraph)
Name Description Heat Shock Protein 1
Chromosomal Location
ChrIV:806621 to 807748 | ORF Map | GBrowse
Gene Ontology Annotations All HSP42 GO evidence and references
  View Computational GO annotations for HSP42
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 30 genes
Classical genetics
Large-scale survey
90 total interaction(s) for 68 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 59
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 1
  • Biochemical Activity: 3
  • PCA: 2
  • Protein-peptide: 1
  • Reconstituted Complex: 2
  • Two-hybrid: 7

Genetic Interactions
  • Dosage Lethality: 1
  • Negative Genetic: 5
  • Phenotypic Enhancement: 4
  • Synthetic Lethality: 2

Expression Summary
Length (a.a.) 375
Molecular Weight (Da) 42,817
Isoelectric Point (pI) 4.84
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIV:806621 to 807748 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1128 806621..807748 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000002578

HSP26 and HSP42 encode the cytosolic members of the small heat shock protein (sHSP) family of molecular chaperones (6, 1). sHSPs bind and prevent unfolded substrate proteins from irreversibly forming large protein aggregates. Bound substrate proteins can eventually be released and refolded in either a spontaneous or chaperone-assisted manner (reviewed in 7). Hsp42p functions in both unstressed and stressed cells, while Hsp26p activity is found only under stress conditions; the target substrate profiles of the two chaperones overlap by approximately 90% (4). Null mutations in hsp26 or hsp42 cause abnormal cell morphology that resembles the effects of dehydration, aging, cytoskeleton damage, or cell wall damage (4).

A basal level of the HSP42 transcript is found under all conditions but expression is induced by stresses such as heat shock, salt shock, and starvation (1). This upregulation of transcription is mediated by the transcription factors Hsf1p and Msn2p/Msn4p which respectively bind heat shock elements and stress elements found in the HSP42 promoter (8, 9). Like other sHSPs, Hsp42p forms a large homo-oligomeric complex; the Hsp42p complex is a ring/barrel-like structure comprised of homodimers (4).

All sHSP chaperones contain a highly conserved alpha-crystallin domain in their C-terminus, and sHSPs have been identified in archaea, plants, insects, cows, and humans (10, 11). Mutations in human sHSPs have been linked to the cardiovascular disorder desmin-related myopathy (OMIM), the neuromuscular disease Charcot-Marie-Tooth disease (OMIM), distal hereditary motor neuropathy (OMIM), and hereditary cataracts (OMIM) (12 and references therein).

Last updated: 2007-07-26 Contact SGD

References cited on this page View Complete Literature Guide for HSP42
1) Wotton D, et al.  (1996) Multimerization of Hsp42p, a novel heat shock protein of Saccharomyces cerevisiae, is dependent on a conserved carboxyl-terminal sequence. J Biol Chem 271(5):2717-23
2) Gu J, et al.  (1997) Small heat shock protein suppression of Vpr-induced cytoskeletal defects in budding yeast. Mol Cell Biol 17(7):4033-42
3) Trotter EW, et al.  (2002) Misfolded proteins are competent to mediate a subset of the responses to heat shock in Saccharomyces cerevisiae. J Biol Chem 277(47):44817-25
4) Haslbeck M, et al.  (2004) Hsp42 is the general small heat shock protein in the cytosol of Saccharomyces cerevisiae. EMBO J 23(3):638-49
5) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
6) Petko L and Lindquist S  (1986) Hsp26 is not required for growth at high temperatures, nor for thermotolerance, spore development, or germination. Cell 45(6):885-94
7) Burnie JP, et al.  (2006) Fungal heat-shock proteins in human disease. FEMS Microbiol Rev 30(1):53-88
8) Amoros M and Estruch F  (2001) Hsf1p and Msn2/4p cooperate in the expression of Saccharomyces cerevisiae genes HSP26 and HSP104 in a gene- and stress type-dependent manner. Mol Microbiol 39(6):1523-32
9) Treger JM, et al.  (1998) Transcriptional factor mutations reveal regulatory complexities of heat shock and newly identified stress genes in Saccharomyces cerevisiae. J Biol Chem 273(41):26875-9
10) White HE, et al.  (2006) Multiple distinct assemblies reveal conformational flexibility in the small heat shock protein Hsp26. Structure 14(7):1197-204
11) Bossier P, et al.  (1989) Structure and expression of a yeast gene encoding the small heat-shock protein Hsp26. Gene 78(2):323-30
12) Ferreira RM, et al.  (2006) Purification and characterization of the chaperone-like Hsp26 from Saccharomyces cerevisiae. Protein Expr Purif 47(2):384-92