title: A GDP/GTP exchange factor involved in linking a spatial landmark to cell polarity.
abstract: In both animal and yeast cells, signaling pathways involving small guanosine triphosphatases (GTPases) regulate polarized organization of the actin cytoskeleton. In the budding yeast Saccharomyces cerevisiae, the Ras-like GTPase Bud1/Rsr1 and its guanosine 5'-diphosphate (GDP)/guanosine 5'-triphosphate (GTP) exchange factor Bud5 are involved in the selection of a specific site for growth, thus determining cell polarity. We found that Bud5 is localized at the cell division site and the presumptive bud site. Its localization is dependent on potential cellular landmarks, such as Bud3 and Axl2/Bud10 in haploid cells and Bud8 and Bud9 in diploid cells. Bud5 also physically interacts with Axl2/Bud10, a transmembrane glycoprotein, suggesting that a receptor-like transmembrane protein recruits a GDP/GTP exchange factor to connect an intrinsic spatial signal to oriented cell growth.
authors: Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210-1292, USA.
authors: P J
authors: PJ
authors: Kang
authors: A
authors: A
authors: Sanson
authors: B
authors: B
authors: Lee
authors: H O
authors: HO
authors: Park
mesh_terms: D002455:Cell Division; D016764:Cell Polarity; D004171:Diploidy; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal / Q000235:genetics; D005838:Genotype; D020662:Guanine Nucleotide Exchange Factors; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006238:Haploidy; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D011233:Precipitin Tests; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: C098775:Axl2 protein, S cerevisiae; C093319:BUD3 protein, S cerevisiae; C091391:BUD5 protein, S cerevisiae; D005656:Fungal Proteins; D020662:Guanine Nucleotide Exchange Factors; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate