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Differential phosphorylation activities of CDK‐activating kinases in Arabidopsis thaliana
Author(s) -
Shimotohno Akie,
Matsubayashi Satoko,
Yamaguchi Masatoshi,
Uchimiya Hirofumi,
Umeda Masaaki
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03780-8
Subject(s) - cyclin dependent kinase , arabidopsis , phosphorylation , kinase , arabidopsis thaliana , biology , microbiology and biotechnology , cyclin dependent kinase 7 , biochemistry , cyclin dependent kinase 2 , protein kinase a , cell cycle , gene , mutant
Activation of cyclin‐dependent kinases (CDKs) requires phosphorylation of a threonine residue within the T‐loop by a CDK‐activating kinase (CAK). Here we isolated an Arabidopsis cDNA ( CAK4At ) whose predicted product shows a high similarity to vertebrate CDK7/p40 MO15 . Northern blot analysis showed that expressions of the four Arabidopsis CAKs ( CAK1At–CAK4At ) were not dependent on cell division. CAK2At‐ and CAK4At‐immunoprecipitates of Arabidopsis crude extract phosphorylated CDK and the carboxy‐terminal domain (CTD) of the largest subunit of RNA polymerase II with different preferences. These results suggest the existence of differential mechanisms in Arabidopsis that control CDK and CTD phosphorylation by multiple CAKs.