FIG. 6.

Enzymatic activity of recombinant S. sciureus p56^lck. The p56^lck enzymes from humans (HLck) and squirrel monkeys (SLck) were transiently expressed in COS-7 cells. In vitro kinase assays (KA) revealed that the recombinant p56^lck enzymes of S. sciureus and H. sapiens had similar activities after immunoprecipitation (IP). Coexpressed Tip from HVS C488 was coprecipitated with p56^lck and served equally well as a substrate for the recombinant p56^lck proteins of S. sciureus and H. sapiens. Thus, the S. sciureus lck gene codes for a functional enzyme. WB, Western blot.