Gene Ontology annotation through association of InterPro records with GO terms
Annotation inferences using phylogenetic trees
Electronic Gene Ontology annotations created by ARBA machine learning models
Combined Automated Annotation using Multiple IEA Methods
A nuclear export signal prevents Saccharomyces cerevisiae Hsp70 Ssb1p from stimulating nuclear localization signal-directed nuclear transport.
Systematic identification of protein complexes in Saccharomyces cerevisiae by mass spectrometry.
The translation machinery and 70 kd heat shock protein cooperate in protein synthesis.
The ribosome-bound chaperones RAC and Ssb1/2p are required for accurate translation in Saccharomyces cerevisiae.
Proteome survey reveals modularity of the yeast cell machinery.
Specific effects of ribosome-tethered molecular chaperones on programmed -1 ribosomal frameshifting.
The plasma membrane proteome of Saccharomyces cerevisiae and its response to the antifungal calcofluor.
Chaperone network in the yeast cytosol: Hsp110 is revealed as an Hsp70 nucleotide exchange factor.
Identification of the divergent calmodulin binding motif in yeast Ssb1/Hsp75 protein and in other HSP70 family members.
Fine-tuning of translation termination efficiency in Saccharomyces cerevisiae involves two factors in close proximity to the exit tunnel of the ribosome.
Proteomic analysis of in vivo 14-3-3 interactions in the yeast Saccharomyces cerevisiae.
Yeast split-ubiquitin-based cytosolic screening system to detect interactions between transcriptionally active proteins.
Yeast Uri1p promotes translation initiation and may provide a link to cotranslational quality control.
Widespread reorganization of metabolic enzymes into reversible assemblies upon nutrient starvation.
A ribosome-anchored chaperone network that facilitates eukaryotic ribosome biogenesis.
The cotranslational function of ribosome-associated Hsp70 in eukaryotic protein homeostasis.
The social and structural architecture of the yeast protein interactome.
In Saccharomyces cerevisiae, the molecular chaperone proteins Ssb1 and Ssb2 upregulate ABC transporter genes, and their upregulation may play a role in the release of quorum-sensing molecules that induce cell growth arrest during the diauxic shift.
-
A 2025 Ssb1/Ssb2 study links the ribosome-associated chaperones to ABC transporter expression and quorum-sensing-molecule release during the diauxic shift, but the evidence is regulatory and does not alter Ssb1's core cotranslational folding annotation.
"Our results show that Ssb1/2 increased the mRNA levels of PDR5, SNQ2, and YOR1 during the late logarithmic growth phase and increased resistance to cycloheximide and fluconazole, possibly via the same pathway as Zuo1 or Ssz1."
Ribosome-associated chaperones integrate co-translational mitochondrial protein import, stress signaling and proteostasis in Saccharomyces cerevisiae.
-
A 2026 abstract reports that Ssb1/Ssb2 support efficient cotranslational handling of mitochondrial precursors and translating-ribosome association with the mitochondrial outer membrane, adding secondary targeting context to the core cytosolic ribosome-associated chaperone role.
"Biochemical analyses further reveal that Ssb1/2 supports the association of translating cytosolic ribosomes with the mitochondrial outer membrane, while NAC loss partially restores this interaction in the absence of Ssb1/2."
The molecular chaperone Ssb from Saccharomyces cerevisiae is a component of the ribosome-nascent chain complex.
The biochemical properties of the ATPase activity of a 70-kDa heat shock protein (Hsp70) are governed by the C-terminal domains.
The Hsp70 homolog Ssb and the 14-3-3 protein Bmh1 jointly regulate transcription of glucose repressed genes in Saccharomyces cerevisiae.
-
Ssb has an extra-ribosomal role in glucose repression by bridging the SNF1 and Glc7 complexes together with Bmh.
"Here we show that the defect in glucose-repression in the absence of Ssb is due to the ability of the chaperone to bridge between the SNF1 and Glc7 complexes."
Profiling Ssb-Nascent Chain Interactions Reveals Principles of Hsp70-Assisted Folding.
-
Ssb repeatedly binds degenerate basic/aromatic motifs as they emerge from the ribosomal tunnel in a RAC-dependent manner.
"Ssb engages most substrates by multiple binding-release cycles to a degenerate sequence enriched in positively charged and aromatic amino acids."
Two chaperones locked in an embrace: structure and function of the ribosome-associated complex RAC.
-
The Zuo1-Ssz1 RAC heterodimer stimulates Ssb ATPase activity to facilitate de novo folding of nascent chains.
"The RAC heterodimer stimulates the ATPase activity of the ribosome-bound Hsp70 homolog Ssb, which interacts with nascent polypeptide chains to facilitate de novo protein folding."
A dual role of the ribosome-bound chaperones RAC/Ssb in maintaining the fidelity of translation termination.
-
RAC-Ssb promotes termination fidelity through direct assistance at stalling-prone nascent chains and through assembly of functional ribosomes.
"Here we show that the RAC/Ssb system promotes the fidelity of translation termination via two distinct mechanisms."
The cotranslational cycle of the ribosome-bound Hsp70 homolog Ssb.
-
Cryo-EM identifies Rpl25/uL23 as the Ssb ribosomal binding site and resolves the RAC-dependent nascent-chain capture cycle.
"Here, we present two cryo-EM structures of the ribosome-bound yeast Hsp70 Ssb, identifying Rpl25/uL23 as the ribosomal binding site and revealing its interaction with a model nascent chain."
OpenScientist GO-focused literature report on SSB1
-
Ssb1's primary function is ATP-dependent cotranslational folding of nascent proteins at cytosolic ribosomes.
"Its primary, defining function is **co-translational protein folding**"
OpenScientist hypothesis report on possible Ssb1/Ssb2 specialization
-
No primary literature demonstrates a paralog-specific substrate preference or cotranslational folding mechanism for Ssb1 versus Ssb2.
"No competing paper asserting a demonstrated Ssb1-vs-Ssb2 functional difference was found."