The yeast endocytic protein Epsin-2 (Ent2) functions in a conserved cell division signaling pathway

MUKHERJEE D; COON BG; EDWARDS III DF; HANNA CB; LONGHI SA; MCCAFFERY JM; WENDLAND B; RETEGUI LA; BI E; AGUILAR RC

JOURNAL OF CELL SCIENCE

The Company of Biologists

Lugar: Cambridge; Año: 2009 vol. 122 p. 2453 - 2463

0021-9533

The epsins are a family of adaptors involved in recruiting otherendocytic proteins, binding of ubiquitylated cargo and inductionof membrane curvature. These molecules bear a characteristicepsin N-terminal homology (ENTH) domain and multiplepeptide motifs that mediate protein-protein interactions. Wehave previously demonstrated that the ENTH domain of epsinis involved in Cdc42 signaling regulation. Here, we presentevidence that yeast epsin 2 (Ent2) plays a signaling role duringcell division. We observed that overexpression of the ENTHdomain of Ent2 (ENTH2), but not Ent1, promoted the formationof chains of cells and aberrant septa. This dominant-negativeeffect resulted from ENTH2-mediated interference with septinassembly pathways. We mapped the ENTH2 determinantsresponsible for induction of the phenotype and found them tobe important for efficient binding to the septin regulatoryprotein, Bem3. Supporting a physiological role for epsin 2 incell division, the protein localized to sites of polarized growthand cytokinesis and rescued a defect in cell division induced byBem3 misregulation. Collectively, our findings provide apotential molecular mechanism linking endocytosis (via epsin2) with signaling pathways regulating cell division.