NONRECEPTOR PROTEIN-TYROSINE KINASE INVOLVEMENT IN SIGNAL-TRANSDUCTION AND IMMUNODEFICIENCY DISEASE

The nonreceptor protein tyrosine kinases (PTKs) have been grouped into 10 different enzyme families based on predicted amino acid sequences. As the number of enzymes belonging to the nonreceptor class of PTK is increasing, one challenge is to determine how these various classes o f PTKs interact within the cell to promote signal transduction. Herein , the activation of four classes of nonreceptor PTKs is discussed in r elation to their interactions with each other as well as with other si gnaling molecules during the process of lymphocyte surface antigen rec eptor-mediated activation. Recent findings of nonreceptor PTK loss-of- function mutations in different immunodeficiency diseases has revealed the important contribution of this group of enzymes to lymphocyte dev elopment. (C) 1995 Academic Press, Inc.