title: The C-terminus of S. pombe DDK subunit Dfp1 is required for meiosis-specific transcription and cohesin cleavage.
abstract: The DDK complex is a conserved kinase complex, consisting of a catalytic subunit, Hsk1 (Cdc7), and its regulatory subunit Dfp1 (Dbf4). This kinase is essential for DNA replication. In this work, we show that dfp1-r35, which truncates the Dfp1 C-terminus zinc finger, causes severe meiotic defects, including reduced spore viability, reduced formation of programmed double strand breaks, altered expression of meiotic genes, and disrupted chromosome segregation. There is a high frequency of dyad formation. Mutants are also defective in the phosphorylation and degradation of the meiotic cohesion, Rec8, resulting in a failure to proceed through the MII division. These defects are more pronounced in a haploid meiosis model than in a normal diploid meiosis. Thus, several critical meiotic functions are linked specifically to the C-terminus of Dfp1, which may target specific substrates for phosphorylation by Hsk1.
authors.affiliation: Program in Molecular and Computational Biology, University of Southern California , Los Angeles, CA 90089-2910 , USA.
authors.forename: Anh-Huy
authors.initials: AH
authors.lastname: Le
authors.forename: Tara L
authors.initials: TL
authors.lastname: Mastro
authors.forename: Susan L
authors.initials: SL
authors.lastname: Forsburg
keywords: Cdc7; Dbf4; Fission yeast; Hsk1; Meiosis; Rec8