A GDP/GTP Exchange Factor Involved in Linking a Spatial Landmark to Cell Polarity

• Published in: Science (American Association for the Advancement of Science) Vol. 292; no. 5520; pp. 1376 - 1378
• Main Authors: Kang, Pil Jung, Sanson, Anthony, Lee, Bongyong, Park, Hay-Oak
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 18.05.2001; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Art and archaeology; Ax12 protein; Biochemistry; Bud10 protein; Bud3 protein; Bud8 protein; Bud9 protein; Budding; Cell Division; Cell Polarity; Cell research; Cells; Cytological research; Cytoskeleton; Daughter cells; Daughters; Diploidy; Fungal Proteins - genetics; Fungal Proteins - metabolism; Genes, Fungal - genetics; Genotype; Geodetic position; guanine nucleotide exchange factor; Guanine Nucleotide Exchange Factors; Guanosine Diphosphate - metabolism; Guanosine Triphosphate - metabolism; Haploidy; Landmarks; Membrane Glycoproteins - genetics; Membrane Glycoproteins - metabolism; Mother cells; Mothers; Mutation - genetics; Plasmids; Precipitin Tests; Protein Binding; Recombinant Fusion Proteins - metabolism; Saccharomyces cerevisiae; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins; Site Selection; Yeasts
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1060360

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.