Control of pre-T cell proliferation and differentiation by the GTPase Rac-I

Nat Immunol. 2000 Oct;1(4):348-52. doi: 10.1038/79808.


The GTPase Rac-I has the potential for pleiotropic functions due to its ability to interact with multiple effectors. Here, activation of Rac-I is shown to potently regulate pre-T cell differentiation and proliferation at the point of T cell antigen receptor (TCR) beta selection. An activated Rac-I effector domain mutant that restricts signaling to particular actions on actin dynamics can drive pre-T cell differentiation. Rac-I activation cannot fully substitute for the pre-TCR complex but can fully correct defects in pre-T cell development in mice lacking the adapter molecule Vav-1. The present study identifies the subset of Rac-I responses that mediate Vav-1 action as critical regulators of TCR beta selection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation / immunology
  • Cell Division / immunology
  • Humans
  • Mice
  • Mutation
  • Receptors, Antigen, T-Cell, alpha-beta / immunology
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*
  • rac1 GTP-Binding Protein / genetics
  • rac1 GTP-Binding Protein / immunology*


  • Receptors, Antigen, T-Cell, alpha-beta
  • rac1 GTP-Binding Protein