Ras regulation and function in lymphocytes.

The GTPase, Ras, is rapidly activated in antigen receptor stimulated T. cells, B cells and mast cells. Ras can bind to diverse effector molecules when activated and thereby switch on multiple downstream effector pathways. In lymphocytes Ras plays an important role in the signalling pathways that activate transcription factors involved in cytokine gene induction. Ras is also a key component of the complex regulatory networks that control T and B cell development.