Review

The Yins of T Cell Activation

See allHide authors and affiliations

Science's STKE  04 Jan 2005:
Vol. 2005, Issue 265, pp. re1
DOI: 10.1126/stke.2652005re1

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Transcription factors activated in response to T cell receptor (TCR) signaling include nuclear factor of activated T cells (NFAT) family, which is highly phosphorylated and thereby maintained in the cytoplasm of resting T cells, the nuclear factor NF-κB, which is kept in the cytoplasm of resting cells through its association with the inhibitor protein IκB, and activating protein–1 (AP-1), which is only transcribed after TCR stimulation. Negative regulators of TCR signaling can be divided into two groups: Class 1 regulators help maintain the quiescent state of unstimulated T cells, whereas class 2 regulators are themselves transcriptionally induced in response to TCR signaling and serve to limit and terminate the activating signal. Class 1 regulators include the autoinhibitory domain of the phosphatase calcineurin; IκB and its transcriptional activators Foxj1 and Foxo3a; and various transcriptional coregulators that inhibit interleukin-2 (IL-2) production. Class 2 regulators include the calcipressins, which, like NFATp and NFAT4 are feedback inhibitors of calcineurin-NFAT signaling, IκB, and the mitogen-activated protein kinase (MAPK) phosphatases, which inhibit MAPK signaling and thus the nuclear localization of AP-1 components.

View Full Text