Coordination of Cytokinesis and Cell Separation by Endosomal Targeting of a Cdc42-specific Guanine Nucleotide Exchange Factor in Ustilago maydis Export

@article{citeulike:4036785, abstract = {The small GTPase Cdc42 is a key regulator of cell polarity and cytoskeletal organization in most eukaryotic cells. In Ustilago maydis, Cdc42 and the guanine nucleotide exchange factor (GEF) Don1 regulate cytokinesis and cell separation. Don1 belongs to the FGD1 family of Cdc42-specific GEFs that are characterized by a C-terminal lipid-binding FYVE domain. Although the FGD1/frabin family of Rho-GEFs is evolutionary conserved from fungi to mammals the role of the FYVE domain for its biological function is unknown. Here, we show that the FYVE domain is specific for phosphatidylinositol-3-phosphate (PtdIns(3)P) and targets Don1 to endosomal vesicles. During cytokinesis asymmetric accumulation of Don1-containing vesicles occurs at the site of septation. We could show that FYVE-dependent localization is critical for the function of Don1 at normal expression levels but can be compensated for by overexpression of Don1 lacking a functional FYVE domain. Our results demonstrate that endosomal compartmentalization of a Cdc42-specific exchange factor is involved in the coordination of cytokinesis and cell separation. 10.1091/mbc.E08-03-0280}, author = {Schink, Kay O. and Bolker, Michael}, citeulike-article-id = {4036785}, citeulike-linkout-0 = {http://dx.doi.org/10.1091/mbc.E08-03-0280}, citeulike-linkout-1 = {http://www.molbiolcell.org/cgi/content/abstract/20/3/1081}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/19073889}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=19073889}, day = {1}, doi = {10.1091/mbc.E08-03-0280}, journal = {Mol. Biol. Cell}, keywords = {cytokinesis, endosomes}, month = {February}, number = {3}, pages = {1081--1088}, posted-at = {2009-02-11 21:11:09}, priority = {2}, title = {Coordination of Cytokinesis and Cell Separation by Endosomal Targeting of a Cdc42-specific Guanine Nucleotide Exchange Factor in Ustilago maydis}, url = {http://dx.doi.org/10.1091/mbc.E08-03-0280}, volume = {20}, year = {2009} }

TY - JOUR ID - citeulike:4036785 L3 - citeulike-article-id:4036785 N2 - The small GTPase Cdc42 is a key regulator of cell polarity and cytoskeletal organization in most eukaryotic cells. In Ustilago maydis, Cdc42 and the guanine nucleotide exchange factor (GEF) Don1 regulate cytokinesis and cell separation. Don1 belongs to the FGD1 family of Cdc42-specific GEFs that are characterized by a C-terminal lipid-binding FYVE domain. Although the FGD1/frabin family of Rho-GEFs is evolutionary conserved from fungi to mammals the role of the FYVE domain for its biological function is unknown. Here, we show that the FYVE domain is specific for phosphatidylinositol-3-phosphate (PtdIns(3)P) and targets Don1 to endosomal vesicles. During cytokinesis asymmetric accumulation of Don1-containing vesicles occurs at the site of septation. We could show that FYVE-dependent localization is critical for the function of Don1 at normal expression levels but can be compensated for by overexpression of Don1 lacking a functional FYVE domain. Our results demonstrate that endosomal compartmentalization of a Cdc42-specific exchange factor is involved in the coordination of cytokinesis and cell separation. 10.1091/mbc.E08-03-0280 IS - 3 JF - Mol. Biol. Cell EP - 1088 TI - Coordination of Cytokinesis and Cell Separation by Endosomal Targeting of a Cdc42-specific Guanine Nucleotide Exchange Factor in Ustilago maydis VL - 20 SP - 1081 KW - cytokinesis KW - endosomes AU - Schink, Kay AU - Bolker, Michael PY - 2009/02/01/ UR - http://dx.doi.org/10.1091/mbc.E08-03-0280 ER -