Gene Ontology annotation through association of InterPro records with GO terms
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Electronic Gene Ontology annotations created by ARBA machine learning models
APC(ste9/srw1) promotes degradation of mitotic cyclins in G(1) and is inhibited by cdc2 phosphorylation.
-
APC/C-Ste9 promotes G1 degradation of the mitotic cyclins Cdc13 and Cig1 but not the S-phase cyclin Cig2, and is dispensable for cyclin proteolysis at the metaphase-anaphase transition.
"We show that APC ste9/srw1 specifically promotes the degradation of mitotic cyclins cdc13 and cig1 but not the S-phase cyclin cig2."
-
Dephosphorylated Ste9 binds the APC/C only in G1; Cdc2-cyclin phosphorylation in the rest of the cycle triggers Ste9 proteolysis and dissociates it from the APC/C.
"In the rest of the cell cycle, phosphorylation of ste9/srw1 by cdc2–cyclin complexes both triggers proteolysis of ste9/srw1 and causes its dissociation from the APC/C."
Fission yeast Fizzy-related protein srw1p is a G(1)-specific promoter of mitotic cyclin B degradation.
-
srw1p is required for Cdc13 degradation during G1 arrest but not at mitotic exit.
"srw1p, a member of the Fizzy-related protein family in fission yeast, is required for the degradation of cdc13p mitotic cyclin B during G 1 arrest."
-
Cdc2-Cdc13 phosphorylates srw1p on four Cdk consensus sites; the unphosphorylatable mutant is stabilised, degrades Cdc13 faster and causes diploidisation.
"Mutant forms of srw1 that could not be phosphorylated on the four Cdk consensus sites in srw1p were more stable than wild-type srw1p: the half-life of the unphosphorylatable srw1p was >120 min, compared with 40 min for wild-type srw1p (Figure 7 B)."
ORFeome cloning and global analysis of protein localization in the fission yeast Schizosaccharomyces pombe.
-
Proteome-wide YFP-tagging localisation study in fission yeast; the source of the nuclear localisation of Ste9/Srw1 recorded by PomBase and UniProt.
"Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein."
Mes1 controls the meiosis I to meiosis II transition by distinctly regulating the anaphase-promoting complex/cyclosome coactivators Fzr1/Mfr1 and Slp1 in fission yeast.
-
With purified fission yeast APC/C, Ste9 is the strongest of the five coactivators at stimulating ubiquitylation of Cut2 and Cdc13 in vitro.
"Ste9 showed the most robust stimulation of ubiquitylation for both substrates."
-
Ste9 activates Cdc13 destruction in interphase but not mitotic extracts, consistent with Cdk-dependent inhibition of Cdh1 orthologues in mitosis.
"In contrast, in interphase egg extracts, Slp1 was unable to activate Cdc13 destruction whereas Ste9 stimulated Cdc13 destruction efficiently (Figure 5C, bottom)."
-
Repressing Ste9 in meiosis stabilises Mes1 at the end of meiosis II.
"In all the mutants (ste9, fzr2Δ, and fzr3Δ), Mes1 levels were significantly increased at the end of meiosis II (5.5–6 h) rather than in early meiosis, pointing to their roles in Mes1 destruction in meiosis II."
A WD repeat protein controls the cell cycle and differentiation by negatively regulating Cdc2/B-type cyclin complexes.
-
srw1 (ste9) was isolated as a multicopy suppressor of hyperactive Cdc2; the disruptant is sterile, fails to arrest in G1 on nitrogen starvation, and does not degrade Cdc13 when starved.
"In the srw1 disruptant, Cdc13 fails to be degraded when cells are starved for nitrogen."
-
Cig2 is degraded on nitrogen starvation regardless of Srw1, so Srw1 restrains Cdc2-Cig2 by a mechanism other than Cig2 destruction.
"Regardless of the presence or absence of Srw1, Cig2 was degraded upon nitrogen starvation, suggesting that Srw1 might inhibit p34 cdc2 /Cig2 by a different mechanism."
Fission yeast Ste9, a homolog of Hct1/Cdh1 and Fizzy-related, is a novel negative regulator of cell cycle progression during G1-phase.
-
ste9 mutants are sterile because they cannot arrest in G1 on starvation; ste9 is synthetically lethal with wee1; ste9 cdc10-ts cells arrested in G1 keep Cdc13 and undergo abortive mitosis; Ste9 overexpression lowers Cdc13 and H1 kinase activity and induces re-replication.
"Overexpression of Ste9 decreased the Cdc13 protein level and the H1-histone kinase activity. In these cells, mitosis was inhibited and an extra round of DNA replication occurred."
Deep research report on Schizosaccharomyces pombe srw1/ste9 (O13286)
-
The MBF activator Rep2 is an APC/C-Ste9 substrate protected during replication arrest by Cds1-mediated phosphorylation and inhibition of Ste9 (Chu et al. 2009).
"During hydroxyurea-induced replication arrest, the Rad3–Cds1 checkpoint protects Rep2 by inhibiting Ste9: Cds1 phosphorylated Ste9 in vitro, and Ste9 phosphorylation/inhibition during arrest depended on Cds1."
-
PP2A-B56 (Par1) is required for Ste9 dephosphorylation, Cdc13 degradation and G1 arrest during nitrogen starvation (Stonyte et al. 2020).
"In nitrogen-starvation time courses extending to 300 minutes, *par1Δ* impaired Ste9 dephosphorylation and Cdc13 degradation and compromised proper G1 arrest."