The kk gene encodes a lymphocyte-specific protein tyrosine kinase of the nonreceptor type that is implicated in signal transduction pathways emanating from the CD4 and CD8 coreceptors. Previous studies also support a role for p56kk in regulating T cell receptor β gene rearrangements and, more generally, thymocyte development. Here we report that a mutant form of p56kk, which is incapable of interacting with CD4 or CD8, behaves indistinguishably from associationcompetent p56kk with respect to its ability to affect thymocyte maturation. The effects of p56kk remained specific in that the closely related src-family kinase p59kk was incapable of substituting for p56kk in arresting β locus gene rearrangements. These data support the view that src-family kinases perform highly specialized and often nonoverlapping functions in hematopoietic cells, and that p56kk acts independently of its association with CD4 and CD8 to regulate thymocyte development.
ASJC Scopus subject areas
- Immunology and Allergy