Genetics, Vol 144, 495-510, Copyright © 1996

INVESTIGATIONS

SEC3 Mutations Are Synthetically Lethal With Profilin Mutations and Cause Defects in Diploid-Specific Bud-Site Selection

B. K. Haarer, A. Corbett, Y. Kweon, A. S. Petzold, P. Silver and S. S. Brown
Department of Anatomy and Cell Biology, University of Michigan, Ann Arbor, Michigan 48109, Division of Biological Sciences, Department of Zoology, and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712

Replacement of the wild-type yeast profilin gene (PFY1) with a mutated form (pfy1-111) that has codon 72 changed to encode glutamate rather than arginine results in defects similar to, but less severe than, those that result from complete deletion of the profilin gene. We have used a colony color-sectoring assay to identify mutations that cause pfy1-111, but not wild-type, cells to be inviable. These profilin synthetic lethal (psl) mutations result in various degrees of abnormal growth, morphology, and temperature sensitivity in PFY1 cells. We have examined psl1 strains in the most detail. Interestingly, these strains display a diploid-specific defect in bud-site selection; haploid strains bud normally, while homozygous diploid strains show a dramatic increase in random budding. We discovered that PSL1 is the late secretory gene, SEC3, and have found that mutations in several other late secretory genes are also synthetically lethal with pfy1-111. Our results are likely to reflect an interdependence between the actin cytoskeleton and secretory processes in directing cell polarity and growth. Moreover, they indicate that the secretory pathway is especially crucial for maintaining budding polarity in diploids.

This article has been cited by other articles:

				S. A. Dighe and K. G. Kozminski Swf1p, a Member of the DHHC-CRD Family of Palmitoyltransferases, Regulates the Actin Cytoskeleton and Polarized Secretion Independently of Its DHHC Motif Mol. Biol. Cell, October 1, 2008; 19(10): 4454 - 4468. [Abstract] [Full Text] [PDF]

				X. Zhang, A. Zajac, J. Zhang, P. Wang, M. Li, J. Murray, D. TerBush, and W. Guo The Critical Role of Exo84p in the Organization and Polarized Localization of the Exocyst Complex J. Biol. Chem., May 27, 2005; 280(21): 20356 - 20364. [Abstract] [Full Text] [PDF]

				M. Murthy, R. Ranjan, N. Denef, M. E. L. Higashi, T. Schupbach, and T. L. Schwarz Sec6 mutations and the Drosophila exocyst complex J. Cell Sci., March 15, 2005; 118(6): 1139 - 1150. [Abstract] [Full Text] [PDF]

				A. Wiederkehr, Y. Du, M. Pypaert, S. Ferro-Novick, and P. Novick Sec3p Is Needed for the Spatial Regulation of Secretion and for the Inheritance of the Cortical Endoplasmic Reticulum Mol. Biol. Cell, December 1, 2003; 14(12): 4770 - 4782. [Abstract] [Full Text] [PDF]

				Y. Dong, D. Pruyne, and A. Bretscher Formin-dependent actin assembly is regulated by distinct modes of Rho signaling in yeast J. Cell Biol., June 23, 2003; 161(6): 1081 - 1092. [Abstract] [Full Text] [PDF]

				J. H. Toikkanen, K. J. Miller, H. Soderlund, J. Jantti, and S. Keranen The {beta} Subunit of the Sec61p Endoplasmic Reticulum Translocon Interacts with the Exocyst Complex in Saccharomyces cerevisiae J. Biol. Chem., May 30, 2003; 278(23): 20946 - 20953. [Abstract] [Full Text] [PDF]

				M. A. Osman, J. B. Konopka, and R. A. Cerione Iqg1p links spatial and secretion landmarks to polarity and cytokinesis J. Cell Biol., November 25, 2002; 159(4): 601 - 611. [Abstract] [Full Text] [PDF]

				J. Jantti, M. K. Aalto, M. Oyen, L. Sundqvist, S. Keranen, and H. Ronne Characterization of temperature-sensitive mutations in the yeast syntaxin 1 homologues Sso1p and Sso2p, and evidence of a distinct function for Sso1p in sporulation J. Cell Sci., January 15, 2002; 115(2): 409 - 420. [Abstract] [Full Text] [PDF]

				J. R. C. Whyte and S. Munro Vesicle tethering complexes in membrane traffic J. Cell Sci., January 7, 2002; 115(13): 2627 - 2637. [Abstract] [Full Text] [PDF]

				A. Saka, M. Abe, H. Okano, M. Minemura, H. Qadota, T. Utsugi, A. Mino, K. Tanaka, Y. Takai, and Y. Ohya Complementing Yeast rho1 Mutation Groups with Distinct Functional Defects J. Biol. Chem., November 30, 2001; 276(49): 46165 - 46171. [Abstract] [Full Text] [PDF]

				J. L. Whitacre, D. A. Davis, K. A. Toenjes, S. M. Brower, and A. E. M. Adams Generation of an Isogenic Collection of Yeast Actin Mutants and Identification of Three Interrelated Phenotypes Genetics, February 1, 2001; 157(2): 533 - 543. [Abstract] [Full Text]

				T. Freedman, A. Porter, and B. Haarer Mutational and hyperexpression-induced disruption of bipolar budding in yeast Microbiology, November 1, 2000; 146(11): 2833 - 2843. [Abstract] [Full Text]

				F. P. Finger and P. Novick Synthetic Interactions of the Post-Golgi sec Mutations of Saccharomyces cerevisiae Genetics, November 1, 2000; 156(3): 943 - 951. [Abstract] [Full Text]

				Y.-J. Sheu, Y. Barral, and M. Snyder Polarized Growth Controls Cell Shape and Bipolar Bud Site Selection in Saccharomyces cerevisiae Mol. Cell. Biol., July 15, 2000; 20(14): 5235 - 5247. [Abstract] [Full Text]

				H. Jin and D. C. Amberg The Secretory Pathway Mediates Localization of the Cell Polarity Regulator Aip3p/Bud6p Mol. Biol. Cell, February 1, 2000; 11(2): 647 - 661. [Abstract] [Full Text]

				D Pruyne and A Bretscher Polarization of cell growth in yeast J. Cell Sci., January 2, 2000; 113(4): 571 - 585. [Abstract] [PDF]

				D. Schott, J. Ho, D. Pruyne, and A. Bretscher The COOH-Terminal Domain of Myo2p, a Yeast Myosin V, Has a Direct Role in Secretory Vesicle Targeting J. Cell Biol., November 15, 1999; 147(4): 791 - 808. [Abstract] [Full Text] [PDF]

				I. Karakesisoglou, K.-P. Janssen, L. Eichinger, A. A. Noegel, and M. Schleicher Identification of a Suppressor of the Dictyostelium Profilin-minus Phenotype as a CD36/LIMP-II Homologue J. Cell Biol., April 5, 1999; 145(1): 167 - 181. [Abstract] [Full Text] [PDF]

				I. J. Blader, M. J. T. V. Cope, T. R. Jackson, A. A. Profit, A. F. Greenwood, D. G. Drubin, G. D. Prestwich, and A. B. Theibert GCS1, an Arf Guanosine Triphosphatase-activating Protein in Saccharomyces cerevisiae, Is Required for Normal Actin Cytoskeletal Organization In Vivo and Stimulates Actin Polymerization In Vitro Mol. Biol. Cell, March 1, 1999; 10(3): 581 - 596. [Abstract] [Full Text]

				J. Jantti, J. Lahdenranta, V. M. Olkkonen, H. Soderlund, and S. Keranen SEM1, a homologue of the split hand/split foot malformation candidate gene Dss1, regulates exocytosis and pseudohyphal differentiation in yeast PNAS, February 2, 1999; 96(3): 909 - 914. [Abstract] [Full Text] [PDF]

				F. P. Finger and P. Novick Spatial Regulation of Exocytosis: Lessons from Yeast J. Cell Biol., August 10, 1998; 142(3): 609 - 612. [Full Text] [PDF]

				B. M. Cali, T. C. Doyle, D. Botstein, and G. R. Fink Multiple Functions for Actin during Filamentous Growth of Saccharomyces cerevisiae Mol. Biol. Cell, July 1, 1998; 9(7): 1873 - 1889. [Abstract] [Full Text]