Role of the F-BAR protein Hof-1 in the regulation of chitin synthesis and cytokinesis in yeast

Remodeling of the plasma membrane and extracellular matrix (ECM) at discrete cellular locations plays important roles in various cellular processes including angiogenesis and cytokinesis. In the budding yeast Saccharomyces cerevisiae, membrane trafficking delivers enzymes essential for the synthesis of the cell-wall (yeast ECM) component chitin to the bud neck at different phases of the cell cycle. During early stages of budding, a Chs3-synthesized chitin ring is deposited at the base of the new bud that is required for bud-neck integrity and normal cell shape. During cytokinesis, actomyosin ring contraction is linked to the formation of a Chs2-synthesized chitinous disk to divide the mother and daughter cells called the primary septum. Chs3-synthesized chitin also plays an auxiliary rote to Chs2 during cytokinesis. Here, I show that the F-BAR protein Hof1 is involved in the endocytic removal of Chs3 from the bud neck alter chitin ring deposition and possibly later after cytokinesis. I also discuss work to show that Hof1 is involved in the localization and function of Inn1, a C2-domain containing protein essential for synthesis of the primary septum during cytokinesis.