GAK: A cyclin G associated kinase contains a tensin/auxilin-like domain

We have cloned a cDNA encoding a novel association partner of cyclin G by West-Western blotting, The cDNA encodes a protein that harbors a Ser/Thr protein kinase-like catalytic domain at the N-terminal, Hence, we named it GAK (cyclin (G) under bar-(a) under bar ssociated (k) under bar inase). The long C-terminal extension shares homology with tensin and auxilin, and contains a leucine zipper region, Co-immunoprecipitation and Western blotting showed that GAK and cyclin G associate together in vivo, GAK also co-precipitated with CDK5, and CDK5 was found to be associated with cyclin G, We also showed by BIAcore analysis that the GAK-cyclin G interaction was direct.