The Budding Yeast Amphiphysin Complex Is Required for Contractile Actin Ring (CAR) Assembly and Post-Contraction GEF-Independent Accumulation of Rho1-GTP

摘要: The late events of the budding yeast cell division cycle, cytokinesis and separation, require assembly a contractile actomyosin ring (CAR), primary secondary septum formation followed by enzymatic degradation septum. Here we present evidence that demonstrates role for amphiphysin complex, heterodimer comprising Rvs167 Rvs161, in CAR separation. iqg1-1 allele is synthetically lethal with both rvs167 rvs161 null mutations. We show Iqg1 complex are required early anaphase but cells able to complete when these activities are, respectively, either compromised or absent. Amphiphysin dependent upon SH3 domain, this function insufficient explain observed synthetic lethality. Dosage suppression endocytosis default separation pathway absence contraction unlikely be maintain viability. normal, post-mitotic, localization Chs3 Rho1 GEF, Rom2, which responsible deposition accumulation GTP bound at bud neck. It concluded failure polarity establishment leads loss viability as result consequent defect.