A Role for the Swe1 Checkpoint Kinase During Filamentous Growth of Saccharomyces cerevisiae

Corresponding author: Curt Wittenberg, Departments of Molecular Biology and Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037., curtw{at}scripps.edu (E-mail)

Communicating editor: S. SANDMEYER

In this study we show that inactivation of Hsl1 or Hsl7, negative regulators of the Swe1 kinase, enhances the invasive behavior of haploid and diploid cells. The enhancement of filamentous growth caused by inactivation of both genes is mediated via the Swe1 protein kinase. Whereas Swe1 contributes noticeably to the effectiveness of haploid invasive growth under all conditions tested, its contribution to pseudohyphal growth is limited to the morphological response under standard assay conditions. However, Swe1 is essential for pseudohyphal differentiation under a number of nonstandard assay conditions including altered temperature and increased nitrogen. Swe1 is also required for pseudohyphal growth in the absence of Tec1 and for the induction of filamentation by butanol, a related phenomenon. Although inactivation of Hsl1 is sufficient to suppress the defect in filamentous growth caused by inactivation of Tec1 or Flo8, it is insufficient to promote filamentous growth in the absence of both factors. Moreover, inactivation of Hsl1 will not bypass the requirement for nitrogen starvation or growth on solid medium for pseudohyphal differentiation. We conclude that the Swe1 kinase modulates filamentous development under a broad spectrum of conditions and that its role is partially redundant with the Tec1 and Flo8 transcription factors.

This article has been cited by other articles:

				H. Helfer and A. S. Gladfelter AgSwe1p Regulates Mitosis in Response to Morphogenesis and Nutrients in Multinucleated Ashbya gossypii Cells Mol. Biol. Cell, October 1, 2006; 17(10): 4494 - 4512. [Abstract] [Full Text] [PDF]

				C. Sgarlata and J. Perez-Martin Inhibitory phosphorylation of a mitotic cyclin-dependent kinase regulates the morphogenesis, cell size and virulence of the smut fungus Ustilago maydis J. Cell Sci., August 15, 2005; 118(16): 3607 - 3622. [Abstract] [Full Text] [PDF]

				D. R. Kellogg Wee1-dependent mechanisms required for coordination of cell growth and cell division J. Cell Sci., December 15, 2003; 116(24): 4883 - 4890. [Abstract] [Full Text] [PDF]

				Y. W. Jiang and C. M. Kang Induction of S. cerevisiae Filamentous Differentiation by Slowed DNA Synthesis Involves Mec1, Rad53 and Swe1 Checkpoint Proteins Mol. Biol. Cell, December 1, 2003; 14(12): 5116 - 5124. [Abstract] [Full Text] [PDF]

				C. Martinez-Anaya, J. R. Dickinson, and P. E. Sudbery In yeast, the pseudohyphal phenotype induced by isoamyl alcohol results from the operation of the morphogenesis checkpoint J. Cell Sci., August 15, 2003; 116(16): 3423 - 3431. [Abstract] [Full Text] [PDF]

				P. J. Cullen and G. F. Sprague Jr. The Glc7p-Interacting Protein Bud14p Attenuates Polarized Growth, Pheromone Response, and Filamentous Growth in Saccharomyces cerevisiae Eukaryot. Cell, December 1, 2002; 1(6): 884 - 894. [Abstract] [Full Text] [PDF]