Identification of a novel Wee1 isoform.
We have identified a novel isoform of Wee1 kinase (Wee1i), which uses Met215 of Wee1 as its initiation codon. RT-PCR, Western blot, and in situ hybridization verified wee1i expression in mammalian cells, rat brain, and rat thymus. Recombinant and partially purified Wee1i from rat thymus displayed kinase activity comparable to or higher than Wee1. The N-terminal 214 residues of Wee1 facilitate its ubiquitin-dependent degradation to trigger mitotic entry. Since Wee1i, lack of these 214 residues, it may evade this degradation and thus provide constitutive Wee1-like kinase activity to inhibit mitotic cell proliferation. Thus, Wee1i may play an important role in differentiation and in tumor suppression.
Yu
Yaping
Y
Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China.
Chen
Biao
B
Chen
Zheng
Z
Fan
Cathy
C
Han
Yifan
Y
Zhang
Jing
J
He
Lizhi
L
Ingram
Alistair
A
Kapoor
Anil
A
Wang
Jerry H
JH
Tang
Damu
D
D000818:Animals; D001921:Brain / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D018387:Codon, Initiator / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D016147:Genes, Tumor Suppressor; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008938:Mitosis / Q000235:genetics* / Q000502:physiology; D041681:NIH 3T3 Cells; D009687:Nuclear Proteins / Q000235:genetics*; D009928:Organ Specificity / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D013950:Thymus Gland / Q000502:physiology
D018797:Cell Cycle Proteins; D018387:Codon, Initiator; D007527:Isoenzymes; D009687:Nuclear Proteins; D011505:Protein-Tyrosine Kinases; C499348:Wee1 protein, mouse