Physical and functional interactions between ZIP kinase and UbcH5.
Zipper-interacting protein kinase (ZIPK) is a widely expressed serine/threonine kinase that has been implicated in cell death and transcriptional regulation, but its mechanism of regulation remains unknown. In our previous study, we showed that leukemia inhibitory factor stimulated threonine-265 phosphorylation of ZIPK, thereby leading to phosphorylation and activation of signal transducer and activator of transcription 3. Here, we identified UbcH5c as a novel ZIPK-binding partner by yeast two-hybrid screening. Importantly, we found that UbcH5c induced ubiquitination of ZIPK. Small-interfering RNA-mediated reduction of endogenous UbcH5 expression decreased ZIPK ubiquitination. Furthermore, coexpression of UbcH5c with ZIPK influenced promyelocytic leukemia protein nuclear body (PML-NB) formation. These results suggest that UbcH5 regulates ZIPK accumulation in PML-NBs by interacting with ZIPK and stimulating its ubiquitination.
Department of Immunology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-Ku Kita 12 Nishi 6, Sapporo 060-0812, Japan.
Norihiko
N
Ohbayashi
Katsuya
K
Okada
Shiho
S
Kawakami
Sumihito
S
Togi
Noriko
N
Sato
Osamu
O
Ikeda
Shinya
S
Kamitani
Ryuta
R
Muromoto
Yuichi
Y
Sekine
Taro
T
Kawai
Shizuo
S
Akira
Tadashi
T
Matsuda
D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002467:Cell Nucleus / Q000201:enzymology*; D064550:Death-Associated Protein Kinases; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism; D000071156:Promyelocytic Leukemia Protein; D034741:RNA, Small Interfering / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
D051017:Apoptosis Regulatory Proteins; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D034741:RNA, Small Interfering; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human; C097310:UBE2D3 protein, human; D044763:Ubiquitin-Conjugating Enzymes; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases