zds1, a novel gene encoding an ortholog of Zds1 and Zds2, controls sexual differentiation, cell wall integrity and cell morphology in fission yeast.
While screening for genes that reverse the sporulation-deficient phenotype of the ras1delta diploid Schizosaccharomyces pombe strain, we identified zds1. This gene shares sequence homology with the ZDS1 and ZDS2 genes from Saccharomyces cerevisiae, which appear to be involved in multiple cellular events. Expression of Zds1 in ras1delta diploid cells elevated their sporulation rate from 0.3 to 11.2%. Expression of the Zds1 C-terminal region increased the sporulation rate further (to 21.9%) while introduction of the Zds1 N-terminal region had no effect. zds1 expression did not induce sporulation in strains with mutations in genes participating in the downstream MAP kinase cascade. The zds1-disrupted strain is sensitive to CaCl2, and this effect is suppressed by the C-terminal region of Zds1. The growth of the zds1delta strain is markedly inhibited by cold temperatures, while its viability decreased in the stationary phase. Moreover, the zds1delta strain is round in shape and very sensitive to zymolyase, and its cell wall becomes thicker than that of wild type. Thus, zds1 must be required to maintain cell wall integrity. The Zds1-GFP fusion protein localized to the cytosol, the septum, and the cell cortex. Its localization in the septum was dependent on its C-terminal region. Overexpression of the C-terminal region of Zds1 induced multi-septa and abnormal zygotes. We propose that the C-terminal region is the functional domain of Zds1 while the N-terminal region is a negative regulatory region. Thus, Zds1 is involved in multiple cellular events in fission yeast, including sexual differentiation, Ca2+ tolerance, cell wall integrity, viability in the stationary phase, and cell morphology.
Yakura
Miyo
M
Department of Life Science and Biotechnology, Shimane University, Matsue 690-8504, Japan.
Ozoe
Fumiyo
F
Ishida
Hideki
H
Nakagawa
Tsuyoshi
T
Tanaka
Katsunori
K
Matsuda
Hideyuki
H
Kawamukai
Makoto
M
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D002118:Calcium / Q000378:metabolism; D002473:Cell Wall / Q000235:genetics* / Q000502:physiology; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000502:physiology; D008969:Molecular Sequence Data; D010641:Phenotype; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012733:Sex Differentiation / Q000235:genetics* / Q000502:physiology; D013172:Spores, Fungal / Q000502:physiology
D048868:Adaptor Proteins, Signal Transducing; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C101740:ZDS1 protein, S cerevisiae; C101741:ZDS2 protein, S cerevisiae; C511069:Zds1 protein, S pombe; D004693:Glucan Endo-1,3-beta-D-Glucosidase; D002118:Calcium