Poster: Cell division

Abs # 670: Functional analysis of patellin1, a cell-plate localized, phosphoinositide-binding protein

Presenter:	Peterman, T. Kaye, kpeterman@wellesley.edu
Authors	Peterman, T. Kaye (A)   Le, Elizabeth  (A)   Pierson, Emily R. (A)   Schlegel, Lotte M. (A)
Affiliations:	(A): Wellesley College

Membrane trafficking is central to the construction of the cell plate during plant cytokinesis. Consequently a detailed understanding of the process depends on the characterization of molecules that function in the formation, transport, targeting and fusion of membrane vesicles to the developing plate, as well as those that participate in its consolidation and maturation into a fully functional partition. Patellin1 (PATL1), is one of a small family of Arabidopsis proteins, characterized by a variable N-terminal domain followed by two domains found in other membrane trafficking proteins (Sec14 and GOLD domains). Localization and biochemical fractionation studies suggest that PATL1 is recruited from the cytoplasm to the expanding and maturing cell plate. In addition PATL1 binds to specific phosphoinositides, important regulators of membrane trafficking. Based on its domain structure, localization patterns and biochemical properties we hypothesize that PATL1 plays a role in membrane trafficking events during the later stages of cytokinesis. Several approaches are being taken to dissect the biological function of the PATLs. A yeast two-hybrid screen is underway to identify proteins that interact with PATL1 and PATL2; their N-terminal domains contain several predicted protein-protein interaction sites including a coiled-coil and proline-rich motifs. Several putative interactors have been identified thus far and one of these interferes with cytokinesis in yeast. Analysis of T-DNA insertion mutants is also underway to determine if the PATLs play an essential role in cytokinesis. Several independent T-DNA insertions, in both the PATL1 and PATL2 genes, have been identified by PCR genotyping. Results from the phenotypic analysis of these mutants will be presented.