GAK: a cyclin G associated kinase contains a tensin/auxilin‐like domain1

Abstract
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 ssociated 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.