A role for the septation initiation network in septum assembly revealed by genetic analysis of sid2-250 suppressors
UMass Chan Affiliations
Department of Molecular Genetics and MicrobiologyDocument Type
Journal ArticlePublication Date
2006-01-18Keywords
ActomyosinAmino Acid Sequence
Crosses, Genetic
Cytokinesis
*Mitosis
Molecular Sequence Data
*Mutation
Phenotype
Protein Structure, Tertiary
Saccharomyces cerevisiae Proteins
Schizosaccharomyces
Schizosaccharomyces pombe Proteins
Temperature
rho GTP-Binding Proteins
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
In the fission yeast Schizosaccharomyces pombe the septation initiation network (SIN) is required for stabilization of the actomyosin ring in late mitosis as well as for ring constriction and septum deposition. In a genetic screen for suppressors of the SIN mutant sid2-250, we isolated a mutation, ace2-35, in the transcription factor Ace2p. Both ace2Delta and ace2-35 show defects in cell separation, and both can rescue the growth defects of some SIN mutants at low restrictive temperatures, where the SIN single mutants lyse at the time of cytokinesis. By detailed analysis of the formation and constriction of the actomyosin ring and septum in the sid2-250 mutant at low restrictive temperatures, we show that the lysis phenotype of the sid2-250 mutant is likely due to a weak cell wall and septum combined with enzymatic activity of septum-degrading enzymes. Consistent with the recent findings that Ace2p controls transcription of genes involved in cell separation, we show that disruption of some of these genes can also rescue sid2-250 mutants. Consistent with SIN mutants having defects in septum formation, many SIN mutants can be rescued at the low restrictive temperature by the osmotic stabilizer sorbitol. The small GTPase Rho1 is known to promote cell wall formation, and we find that Rho1p expressed from a multi-copy plasmid can also rescue sid2-250 at the low restrictive temperature. Together these results suggest that the SIN has a role in promoting proper cell wall formation at the division septa.Source
Genetics. 2006 Apr;172(4):2101-12. Epub 2006 Jan 16. Link to article on publisher's site
DOI
10.1534/genetics.105.050955Permanent Link to this Item
http://hdl.handle.net/20.500.14038/42237PubMed ID
16415366Related Resources
ae974a485f413a2113503eed53cd6c53
10.1534/genetics.105.050955