PMID:14699070

Citation	Carmichael, JB, Provost, P, Ekwall, K and Hobman, TC (2004) ago1 and dcr1, two core components of the RNA interference pathway, functionally diverge from rdp1 in regulating cell cycle events in Schizosaccharomyces pombe. Mol. Biol. Cell 15:1425-35
Abstract	In the fission yeast Schizosaccharomyces pombe, three genes that function in the RNA interference (RNAi) pathway, ago1+, dcr1+, and rdp1+, have recently been shown to be important for timely formation of heterochromatin and accurate chromosome segregation. In the present study, we present evidence that null mutants for ago1+ and dcr1+ but not rdp1+, exhibit abnormal cytokinesis, cell cycle arrest deficiencies, and mating defects. Subsequent analyses showed that ago1+ and dcr1+ are required for regulated hyperphosphorylation of Cdc2 when encountering genotoxic insults. Because rdp1+ is dispensable for this process, the functions of ago1+ and dcr1+ in this pathway are presumably independent of their roles in RNAi-mediated heterochromatin formation and chromosome segregation. This was further supported by the finding that ago1+ is a multicopy suppressor of the S-M checkpoint deficiency and cytokinesis defects associated with loss of Dcr1 function, but not for the chromosome segregation defects of this mutant. Accordingly, we conclude that Dcr1-dependent production of small interfering RNAs is not required for enactment and/or maintenance of certain cell cycle checkpoints and that Ago1 and Dcr1 functionally diverge from Rdp1 to control cell cycle events in fission yeast. Finally, exogenous expression of hGERp95/EIF2C2/hAgo2, a human Ago1 homolog implicated in posttranscriptional gene silencing, compensated for the loss of ago1+ function in S. pombe. This suggests that PPD proteins may also be important for regulation of cell cycle events in higher eukaryotes.
Links	PubMed PMC363162 Online version:10.1091/mbc.E03-06-0433
Keywords	Adenosine Triphosphatases/metabolism; Argonaute Proteins; CDC2 Protein Kinase/metabolism; Cell Cycle/physiology; GPI-Linked Proteins; Heterochromatin/metabolism; Mutation/genetics; Phosphorylation; Protein Structure, Tertiary/physiology; RNA, Small Interfering/metabolism; RNA-Binding Proteins; Receptors, Tumor Necrosis Factor/metabolism; Schizosaccharomyces/metabolism; Schizosaccharomyces pombe Proteins/metabolism; Tumor Necrosis Factor Decoy Receptors
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
SCHPO:DCR1	involved_in	GO:0035389: establishment of chromatin silencing at silent mating-type cassette	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete

References

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