Interaction of the CDK2-associated protein-1, p12 super(DOC-1/CDK2AP1), with its homolog, p14 super(DOC-1R)

• Published in: Biochemical and biophysical research communications Vol. 315; no. 4; pp. 998 - 1003
• Main Authors: Buajeeb, W, Zhang, X, Ohyama, H, Han, D, Surarit, R, Kim, Y, Wong, D T
• Format: Journal Article
• Language: English
• Published: 19.03.2004
• ISSN: 0006-291X
• DOI: 10.1016/j.bbrc.2004.02.003

Human DOC-1/CDK2AP1 gene encodes a growth suppressor protein of 12kDa (p12 super(DOC-1/CDK2AP1)). Recently, p12 super(DOC-1/CDK2AP1) has been shown to associate with cell cycle proteins including CDK2 and DNA polymerase alpha /primase. It negatively regulates CDK2 activities and suppresses DNA replication. Therefore, identification of other p12 super(DOC-1/CDK2AP1) interacting proteins might clarify its role in the cell cycle regulation and carcinogenesis. The purpose of this study was to identify additional p12 super(DOC-1/CDK2AP1) interacting proteins using the yeast two-hybrid system. Using human p12 super(DOC-1 /CDK2AP1) as a bait in a liver cDNA library screening, cDNA clones identical to human DOC-1R transcript were identified. The interaction between p12 super(DOC-1/CDK2AP1) and p14 super(DOC-1R) was verified in vitro and in cells. GST pull-down assay and immunoprecipitation experiments confirmed the interaction between the two proteins. The critical region for p12 super(DOC-1/CDK2AP1)'s interaction with p14 super(DOC-1R) was defined to amino acids 20-25 by using a series of deletion mutants as baits in the yeast two-hybrid system. Our data indicated that p12 super(DOC-1/CDK2AP1) could associate with its homologous protein, p14 super(DOC-1R).