A complex role of Arabidopsis CDKD;3 in meiotic progression and cytokinesis

Abstract

Meiosis is a specialized cell division that halves the number of chromosomes in two consecutive rounds of chromosome segregation. In angiosperm plants is meiosis followed by mitotic divisions to form rudimentary haploid gametophytes. In Arabidopsis, termination of meiosis and transition to gametophytic development are governed by TDM1 and SMG7 that mediate inhibition of translation. Mutants deficient in this mechanism do not form tetrads but instead undergo multiple cycles of aberrant nuclear divisions that are likely caused by the failure to downregulate cyclin dependent kinases during meiotic exit. A suppressor screen to identify genes that contribute to meiotic exit uncovered a mutation in cyclin‐dependent kinase D;3 (CDKD;3) that alleviates meiotic defects in smg7 deficient plants. The CDKD;3 deficiency prevents aberrant meiotic divisions observed in smg7 mutants or delays their onset after initiation of cytokinesis, which permits formation of functional microspores. Although CDKD;3 acts as an activator of cyclin‐dependent kinase A;1 (CDKA;1), the main cyclin dependent kinase that regulates meiosis, cdkd;3 mutation appears to promote meiotic exit independently of CDKA;1. Furthermore, analysis of CDKD;3 interactome revealed enrichment for proteins implicated in cytokinesis, suggesting a more complex function of CDKD;3 in cell cycle regulation.

A new mechanism of posttranslational polyglutamylation regulates phase separation and signaling of the Wnt pathway protein Dishevelled

“…Dynamic exclusion was enabled for 60 s after one MS/MS spectra acquisition. The isolation window for MS/MS fragmentation was set to 1.6 m/z ( 75 ).…”

“…Match between runs was set among all analyzed samples. Protein abundance was assessed using protein intensities calculated by MaxQuant ( 75 ). The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE ( 74 ) partner repository with the dataset identifier PXD033548.…”

“…ion searches were done against modified cRAP database (based on http://www.thegpm.org/crap) containing protein contaminants like keratin, trypsin etc., and Match between runs was set among all analyzed samples. Protein abundance was assessed using protein intensities calculated by MaxQuant74 . The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE73 partner repository with the dataset identifier PXD033548.…”