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Pob1 participates in the Cdc42 regulation of fission yeast actin cytoskeleton.
- Source :
-
Molecular biology of the cell [Mol Biol Cell] 2009 Oct; Vol. 20 (20), pp. 4390-9. Date of Electronic Publication: 2009 Aug 26. - Publication Year :
- 2009
-
Abstract
- Rho GTPases regulate the actin cytoskeleton in all eukaryotes. Fission yeast Cdc42 is involved in actin cable assembly and formin For3 regulation. We isolated cdc42-879 as a thermosensitive strain with actin cable and For3 localization defects. In a multicopy suppressor screening, we identified pob1(+) as suppressor of cdc42-879 thermosensitivity. Pob1 overexpression also partially restores actin cables and localization of For3 in the mutant strain. Pob1 interacts with Cdc42 and this GTPase regulates Pob1 localization and/or stability. The C-terminal pleckstrin homology (PH) domain of Pob1 is required for Cdc42 binding. Pob1 also binds to For3 through its N-terminal sterile alpha motif (SAM) domain and contributes to the formin localization at the cell tips. The previously described pob1-664 mutant strain (Mol. Biol. Cell. 10, 2745-2757, 1999), which carries a mutation in the PH domain, as well as pob1 mutant strains in which Pob1 lacks the N-terminal region (pob1DeltaN) or the SAM domain (pob1DeltaSAM), have cytoskeletal defects similar to that of cdc42-879 cells. Expression of constitutively active For3DAD* partially restores actin organization in cdc42-879, pob1-664, pob1DeltaN, and pob1DeltaSAM. Therefore, we propose that Pob1 is required for For3 localization to the tips and facilitates Cdc42-mediated relief of For3 autoinhibition to stimulate actin cable formation.
- Subjects :
- Actin Cytoskeleton metabolism
Actins metabolism
Amino Acid Substitution
Cell Cycle Proteins chemistry
Cell Cycle Proteins physiology
Cell Polarity
Formins
Gene Expression Regulation, Fungal
Guanosine Triphosphate physiology
Protein Interaction Mapping
Protein Structure, Tertiary
Schizosaccharomyces ultrastructure
Schizosaccharomyces pombe Proteins chemistry
Schizosaccharomyces pombe Proteins genetics
cdc42 GTP-Binding Protein chemistry
cdc42 GTP-Binding Protein genetics
rho GTP-Binding Proteins chemistry
Actin Cytoskeleton ultrastructure
Cytoskeleton ultrastructure
Schizosaccharomyces metabolism
Schizosaccharomyces pombe Proteins physiology
cdc42 GTP-Binding Protein physiology
rho GTP-Binding Proteins physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1939-4586
- Volume :
- 20
- Issue :
- 20
- Database :
- MEDLINE
- Journal :
- Molecular biology of the cell
- Publication Type :
- Academic Journal
- Accession number :
- 19710424
- Full Text :
- https://doi.org/10.1091/mbc.E09-03-0207