Protein phosphatase type 1-interacting protein Ysw1 is involved in proper septin organization and prospore membrane formation during sporulation.
Sporulation of Saccharomyces cerevisiae is a developmental process in which four haploid spores are generated inside a diploid cell. Gip1, a sporulation-specific targeting subunit of protein phosphatase type 1, together with its catalytic subunit, Glc7, colocalizes with septins along the extending prospore membrane and is required for septin organization and spore wall formation. However, the mechanism by which Gip1-Glc7 phosphatase promotes these events is unclear. We show here that Ysw1, a sporulation-specific coiled-coil protein, has a functional relationship to Gip1-Glc7 phosphatase. Overexpression of YSW1 partially suppresses the sporulation defect of a temperature-sensitive allele of gip1. Ysw1 interacts with Gip1 in a two-hybrid assay, and this interaction is required for suppression. Ysw1 tagged with green fluorescent protein colocalizes with septins and Gip1 along the extending prospore membrane during spore formation. Sporulation is partially defective in ysw1Delta mutant, and cytological analysis revealed that septin structures are perturbed and prospore membrane extension is aberrant in ysw1Delta cells. These results suggest that Ysw1 functions with the Gip1-Glc7 phosphatase to promote proper septin organization and prospore membrane formation.
Ishihara
Makoto
M
Laboratory of Biological Chemistry, Graduate School of Agriculture and Life Science, The University of Tokyo, Tokyo 113-8657, Japan.
Suda
Yasuyuki
Y
Inoue
Ichiro
I
Tanaka
Takayuki
T
Takahashi
Tetsuo
T
Gao
Xiao-Dong
XD
Fukui
Yasuhisa
Y
Ihara
Sayoko
S
Neiman
Aaron M
AM
Tachikawa
Hiroyuki
H
D021581:Active Transport, Cell Nucleus / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D016153:Genes, Suppressor / Q000502:physiology*; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008540:Meiosis / Q000235:genetics; D008969:Molecular Sequence Data; D054645:Protein Phosphatase 1 / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D012100:Reproduction, Asexual / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013172:Spores, Fungal / Q000378:metabolism* / Q000648:ultrastructure
D029701:Saccharomyces cerevisiae Proteins; C544703:Ysw1 protein, S cerevisiae; C442840:GIP1 protein, S cerevisiae; C092048:GLC7 protein, S cerevisiae; D054645:Protein Phosphatase 1