In vitro phosphorylation of ASY1 by CDKA;1

ABSTRACT: Meiosis is a complex cell division program reducing chromosome number as a prerequisite for sexual reproduction and at the same time leading to a new combination of parental alleles contributing to biodiversity. Little is known about how the distinct order of the molecular processes of meiosis are orchestrated. Here we show that the Arabidopsis Cdk1/Cdk2 homolog CDKA;1 is a master regulator of meiosis needed for several aspects of meiosis such as chromosome synapsis. We identify the chromosome axis protein ASYNAPTIC 1 (ASY1), the Arabidopsis Hop1 homolog, which is required for synaptonemal complex formation, as a phospho-target of CDKA;1. Live cell imaging together with biochemical assays shows that CDK-dependent phosphorylation of ASY1 is required for its recruitment to the chromosome axis via ASYNAPTIC 3 (ASY3), the Arabidopsis Red1 homolog, counteracting the disassembly activity of the AAA+ ATPase PACHYTENE CHECKPOINT 2 (PCH2). Furthermore, we have mapped the closure motif of ASY1, typical for HORMA domain proteins, and provide evidence that the Cdk-dependent phosphorylation of ASY1 regulates the self-polymerization of ASY1 along the chromosome axis during early meiosis. Hence, the phosphorylation of ASY1 by CDKA;1 appears to be a two-pronged mechanism to initiate chromosome axis formation in meiosis.

ORGANISM(S): Arabidopsis Thaliana

SUBMITTER: Sara Stolze  

PROVIDER: PXD011335 | panorama | Tue Oct 01 00:00:00 BST 2019

REPOSITORIES: PanoramaPublic