title: The C-terminal kinase domain of the p34cdc2-related PITSLRE protein kinase (p110C) associates with p21-activated kinase 1 and inhibits its activity during anoikis.
abstract: The PITSLRE protein kinases are parts of the large family of p34cdc2-related kinases. During apoptosis induced by some stimuli, specific PITSLRE isoforms are cleaved by caspase to produce a protein that contains the C-terminal kinase domain of the PITSLRE proteins (p110C). The p110C induces apoptosis when it is ectopically expressed in Chinese hamster ovary cells. In our study, similar induction of this p110C was observed during anoikis in NIH3T3 cells. To investigate the molecular mechanism of apoptosis mediated by p110C, we used the yeast two-hybrid system to screen a human fetal liver cDNA library and identified p21-activated kinase 1 (PAK1) as an interacting partner of p110C. The association of p110C with PAK1 was further confirmed by in vitro binding assay, in vivo coimmunoprecipitation, and confocal microscope analysis. The interaction of p110C with PAK1 occurred within the residues 210-332 of PAK1. Neither association between p58PITSLRE or p110PITSLRE and PAK1 nor association between p110C and PAK2 or PAK3 was observed. Anoikis was increased and PAK1 activity was inhibited when NIH3T3 cells were transfected with p110C. Furthermore, the binding of p110C with PAK1 and inhibition of PAK1 activity were also observed during anoikis. Taken together, these data suggested that PAK1 might participate in the apoptotic pathway mediated by p110C.
authors.affiliation: Department of Biochemistry, Shanghai Medical Center, Fudan University (formerly the Shanghai Medical University), People's Republic of China.
authors.forename: She
authors.initials: S
authors.lastname: Chen
authors.forename: Xianglei
authors.initials: X
authors.lastname: Yin
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Yan
authors.forename: Shuying
authors.initials: S
authors.lastname: Ji
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.forename: Mingmei
authors.initials: M
authors.lastname: Cai
authors.forename: Songwen
authors.initials: S
authors.lastname: Zhang
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zong
authors.forename: Yun
authors.initials: Y
authors.lastname: Hu
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Yuan
authors.forename: Zonghou
authors.initials: Z
authors.lastname: Shen
authors.forename: Jianxin
authors.initials: J
authors.lastname: Gu
mesh_terms: D016475:3T3 Cells; D000818:Animals; D023102:Anoikis; D001483:Base Sequence; D016466:CHO Cells; D006224:Cricetinae; D018844:Cyclin-Dependent Kinases / Q000502:physiology*; D017931:DNA Primers; D051379:Mice; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction; D054462:p21-Activated Kinases
chemical_list: D017931:DNA Primers; C515903:PAK1 protein, human; C515905:Pak1 protein, mouse; D017346:Protein Serine-Threonine Kinases; D054462:p21-Activated Kinases; C447612:CDK11a protein, human; D018844:Cyclin-Dependent Kinases