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The regulatory subunits of fission yeast protein phosphatase 2A (PP2A) affect cell morphogenesis, cell wall synthesis and cytokinesis
Author(s) -
Kinoshita Kazuhisa,
Nemoto Takeshi,
Nabeshima Kentaro,
Kondoh Hiroshi,
Niwa Hajime,
Yanagida Mitsuhiro
Publication year - 1996
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1046/j.1365-2443.1996.02002.x
Subject(s) - cytokinesis , biology , protein phosphatase 2 , schizosaccharomyces pombe , microbiology and biotechnology , mitosis , protein subunit , actin , morphogenesis , schizosaccharomyces , microtubule , cell polarity , gene , genetics , cell division , saccharomyces cerevisiae , cell
Background: Protein phosphatase 2A (PP2A) holoenzymes have a trimeric structure, consisting of a catalytic subunit C and two regulatory subunits A (PR65) and B (PR55). In fission yeast the C subunits, being 80% identical to their mammalian counterparts, are essential for viability and negatively regulate the entry into mitosis. Genetic analyses in budding yeast and Drosophila show that the regulatory subunits are implicated in chromosome segregation, cell morphogenesis and/or cytokinesis. Results: We isolated fission yeast genes paa1 + and pab1 + encoding the regulatory subunits PR65 and PR55, respectively. Gene disruption showed that the paa1 + gene was essential for viability while pab1 + was not required at 26–33°C. Microtubule and actin distributions were anomalous in gene disrupted Δ paa1 cells which were incapable of forming a polarized cell shape. Gene disrupted Δ pab1 cells were pear‐ or round‐shaped, and lost the polar distributions of actin and microtubules. In addition, Δ pab1 cells were defective in cell wall synthesis and sporulation at permissive temperatures. At restrictive temperatures, Δ pab1 cells showed an osmoremedial temperature‐sensitive phenotype and delayed in cytokinesis. However, chromosome segregation was normal. Conclusion: Fission yeast PPZA regulatory subunit plays a critical role in cell morphogenesis, probably through regulation of the cytoskeletal network and cell wall synthesis.