CDKG1in Arabidopsis Thaliana Is Required For The Pre-mRBA Splicing Including CalS5

Cyclin-dependent kinase G1belongs to a member of the family that wasoriginally characterized as the cell cycle regulator. In this study, we report that CDKG1in Arabidopsis thaliana regulates the pre-mRNA splicing of CalS5, and thereforeinvolves in early pollen wall formation. CDKG1which contains N-terminal Ser/Arg(RS)motifs can regulates proper splicing through the interaction with a splicing factorRSZ33. A cyclin RCY1functioning as a regulatory subunit interacts with CDKG1and forms CDKG1-RCY1complex which ensures the kinase activity of CDKG1. Theknockout mutation showed seriously male sterility due to the microspore abortionafter meiosis. Further studies suggest that in the mutation CalS5is abnormal in thesplicing of its intron6, resulting in down regulation of the CalS5mature mRNAsignificantly. RNA immunoprecipitation analysis suggests that CDKG1isassociated with this intron as well as some other GC-AG type introns. Wedemonstrate the prediction of CDKG1on the specially regulation to alternativesplicing of other potential sites through deep RNA-sequencing. In the subsequenceanalysis we may also discover some other functions and the potential action sites ofCDKG1.The direct genetic biochemistry proofs indicates for CDKG1involving inpre-mRNA splicingshow that CDK are not only transcription regulators but also splicing regulators.