Nucleolar Nek11 is a novel target of Nek2A in G1/S-arrested cells.
We previously reported that Nek11, a member of the NIMA (never-in-mitosis A) family of kinases, is activated in G(1)/S-arrested cells. We provide herein several lines of evidence for a novel interaction between Nek11 and Nek2A. Both Nek11 and Nek2A, but not Nek2B, were detected at nucleoli, and the Nek2A-specific C-terminal end (amino acids 399-445) was responsible for nucleolar localization. Endogenous Nek11 coimmunoprecipitated with endogenous Nek2A, and non-catalytic regions of each kinase were involved in the complex formation. Nek11L interacted with phosphorylated Nek2A but barely with the kinase-inactive Nek2A (K37R) mutant. In addition, both Nek2A autophosphorylation activity and the Nek11L-Nek2A complex formation increased in G(1)/S-arrested cells. These results indicate that autophosphorylation of Nek2A could stimulate its interaction with Nek11L at the nucleolus. Moreover, Nek2 directly phosphorylated Nek11 in the C-terminal non-catalytic region and elevated Nek11 kinase activity. The non-catalytic region of Nek11 showed autoinhibitory activity through intramolecular interaction with its N-terminal catalytic domain. Nek2 dissociated this autoinhibitory interaction. Altogether, our studies demonstrate a unique mechanism of Nek11 activation by Nek2A in G(1)/S-arrested cells and suggest a novel possibility for nucleolar function of the NIMA family.
Noguchi
Kohji
K
Department of Bioactive Molecules, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Fukazawa
Hidesuke
H
Murakami
Yuko
Y
Uehara
Yoshimasa
Y
D015153:Blotting, Western; D002384:Catalysis; D020134:Catalytic Domain; D002460:Cell Line; D045744:Cell Line, Tumor; D002466:Cell Nucleolus / Q000378:metabolism*; D002478:Cells, Cultured; D016193:G1 Phase; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009154:Mutation; D000072379:NIMA-Related Kinases; D017830:Octoxynol / Q000494:pharmacology; D019606:Phosphoamino Acids / Q000737:chemistry; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016196:S Phase; D014162:Transfection
D005982:Glutathione Transferase; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D000072379:NIMA-Related Kinases; D017830:Octoxynol; D019606:Phosphoamino Acids; D011494:Protein Kinases; D011993:Recombinant Fusion Proteins; C469355:NEK11 protein, human