SIS1/YNL007C Summary Help

Standard Name SIS1 1
Systematic Name YNL007C
Feature Type ORF, Verified
Description Type II HSP40 co-chaperone that interacts with the HSP70 protein Ssa1p; shuttles between cytosol and nucleus; mediates delivery of misfolded proteins into the nucleus for degradation; involved in proteasomal degradation of misfolded cytosolic proteins; protein abundance increases in response to DNA replication stress; polyQ aggregates sequester Sis1p and interfere with clearance of misfolded proteins; similar to bacterial DnaJ proteins and mammalian DnaJB1 (2, 3, 4, 5, 6 and see Summary Paragraph)
Name Description SIt4 Suppressor 1
Chromosomal Location
ChrXIV:619565 to 618507 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gbrowse
Genetic position: 3 cM
Gene Ontology Annotations All SIS1 GO evidence and references
  View Computational GO annotations for SIS1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 8 genes
Resources
Classical genetics
null
overexpression
repressible
Large-scale survey
conditional
null
reduction of function
repressible
Resources
107 total interaction(s) for 69 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 32
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 13
  • Biochemical Activity: 9
  • Co-crystal Structure: 1
  • Co-purification: 1
  • PCA: 9
  • Protein-peptide: 2
  • Reconstituted Complex: 9
  • Two-hybrid: 2

Genetic Interactions
  • Dosage Lethality: 1
  • Dosage Rescue: 10
  • Negative Genetic: 1
  • Phenotypic Enhancement: 3
  • Phenotypic Suppression: 4
  • Positive Genetic: 3
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 2

Resources
Expression Summary
histogram
Resources
Length (a.a.) 352
Molecular Weight (Da) 37,590
Isoelectric Point (pI) 9.86
Localization
Phosphorylation PhosphoGRID | PhosphoPep Database
Structure
Homologs
sequence information
ChrXIV:619565 to 618507 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
SGD ORF map
Genetic position: 3 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Relative
Coordinates
Chromosomal
Coordinates
Most Recent Updates
Coordinates Sequence
CDS 1..1059 619565..618507 2011-02-03 1997-01-28
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
Resources
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000004952
SUMMARY PARAGRAPH for SIS1

Hsp40/DnaJ is a family of proteins, established by bacterial DnaJ, that regulates Hsp70 chaperone activity. Hsp40s stimulate the intrinsically weak ATPase activity of Hsp70 proteins and facilitate Hsp70 interaction with polypeptide substrates. Hsp70 family members often have multiple Hsp40 partners, and these specific pairings govern Hsp70 chaperone involvement in particular processes (reviewed in 7, 8, and 9). All Hsp40s contain a highly conserved 75-amino acid J domain, which interacts with the ATPase domain of Hsp70 to stimulate ATP hydrolysis. However, there are also other conserved structural domains, and based on the presence or absence of these regions, the Hsp40 family can be divided into three subtypes: type I, type II and type III (a comprehensive overview of the structural features of the different HSP40 subtypes can be found in 9). Sequence analysis of the S. cerevisiae genome has revealed 22 proteins in the Hsp40/DnaJ family: YDJ1, XDJ1, APJ1, SIS1, DJP1, ZUO1, SWA2, JJJ1, JJJ2, JJJ3, CAJ1, CWC23, MDJ1, MDJ2, PAM18, JAC1, JID1, SCJ1, HLJ1, JEM1, SEC63, and ERJ5 (9).

Last updated: 2006-12-19 Contact SGD

References cited on this page View Complete Literature Guide for SIS1
1) Luke MM, et al.  (1991) Characterization of SIS1, a Saccharomyces cerevisiae homologue of bacterial dnaJ proteins. J Cell Biol 114(4):623-38
2) Lu Z and Cyr DM  (1998) Protein folding activity of Hsp70 is modified differentially by the hsp40 co-chaperones Sis1 and Ydj1. J Biol Chem 273(43):27824-30
3) Fan CY, et al.  (2004) Exchangeable chaperone modules contribute to specification of type I and type II Hsp40 cellular function. Mol Biol Cell 15(2):761-73
4) 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
5) Summers DW, et al.  (2013) The Type II Hsp40 Sis1 cooperates with Hsp70 and the E3 ligase Ubr1 to promote degradation of terminally misfolded cytosolic protein. PLoS One 8(1):e52099
6) Park SH, et al.  (2013) PolyQ Proteins Interfere with Nuclear Degradation of Cytosolic Proteins by Sequestering the Sis1p Chaperone. Cell 154(1):134-45
7) Qiu XB, et al.  (2006) The diversity of the DnaJ/Hsp40 family, the crucial partners for Hsp70 chaperones. Cell Mol Life Sci 63(22):2560-2570
8) Cyr DM, et al.  (1994) DnaJ-like proteins: molecular chaperones and specific regulators of Hsp70. Trends Biochem Sci 19(4):176-81
9) Walsh P, et al.  (2004) The J-protein family: modulating protein assembly, disassembly and translocation. EMBO Rep 5(6):567-71