CASK inhibits ECV304 cell growth and interacts with Id1.
Calcium/calmodulin-dependent serine protein kinase (CASK) is generally known as a scaffold protein. Here we show that overexpression of CASK resulted in a reduced rate of cell growth, while inhibition of expression of endogenous CASK via RNA-mediated interference resulted in an increased rate of cell growth in ECV304 cells. To explore the molecular mechanism, we identified a novel CASK-interacting protein, inhibitor of differentiation 1 (Id1) with a yeast two-hybrid screening. Furthermore, endogenous CASK and Id1 proteins were co-precipitated from the lysates of ECV304 cells by immunoprecipitation. Mammalian two-hybrid protein-protein interaction assays indicated that CASK possessed a different binding activity for Id1 and its alternative splicing variant. It is known that Id proteins play important roles in regulation of cell proliferation and differentiation. Thus, we speculate that the regulation of cell growth mediated by CASK may be involved in Id1. Our findings indicate a novel function of CASK, the mechanism that remains to be further investigated.
Qi
Jie
J
Burn Research Institute, Southwest Hospital, Third Military Medical University, State Key Laboratory of Trauma, Burn and Combined Injury, Chongqing 400038, PR China.
Su
Yongyue
Y
Sun
Rongju
R
Zhang
Fang
F
Luo
Xiaofeng
X
Yang
Zongcheng
Z
Luo
Xiangdong
X
D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation; D042783:Endothelial Cells / Q000502:physiology*; D051528:Guanylate Kinases; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1; D025941:Protein Interaction Mapping; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
C497453:ID1 protein, human; D051798:Inhibitor of Differentiation Protein 1; D012097:Repressor Proteins; D014157:Transcription Factors; C106868:CASK kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D051528:Guanylate Kinases