Regulation of the polarization of T cells toward antigen-presenting cells by Ras-related GTPase CDC42.
AUTOR(ES)
Stowers, L
RESUMO
The mechanisms by which cells rapidly polarize in the direction of external signals are not understood. Helper T cells, when contacted by an antigen-presenting cell, polarize their cytoskeletons toward the antigen-presenting cell within minutes. Here we show that, in T cells, the mammalian Ras-related GTPase CDC42 (the homologue of yeast CDC42, a protein involved in budding polarity) can regulate the polarization of both actin and microtubules toward antigen-presenting cells but is not involved in other T-cell signaling processes such as those which culminate in interleukin 2 production. Although T-cell polarization appears dispensable for signaling leading to interleukin 2 production, polarization may direct lymphokine secretion towards the correct antigen-presenting cell in a crowded cellular environment. Inhibitor experiments suggest that phosphatidylinositol 3-kinase is required for cytoskeletal polarization but that calcineurin activity, known to be important for other aspects of signaling, is not. Apparent conservation of CDC42 function between yeast and T cells suggests that this GTPase is a general regulator of cytoskeletal polarity in many cell types.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=41841Documentos Relacionados
- RanGAP1 induces GTPase activity of nuclear Ras-related Ran.
- Antigen-presenting cells control T cell proliferation by regulating amino acid availability
- The specific direct interaction of helper T cells and antigen-presenting B cells.
- Characterization of a guanine nucleotide dissociation stimulator for a ras-related GTPase.
- Multicopy suppression of the cdc24 budding defect in yeast by CDC42 and three newly identified genes including the ras-related gene RSR1.