Inhibition of the kinase Csk in thymocytes reveals a requirement for actin remodeling in the initiation of full TCR signaling

Ying Xim Tan; Boryana N Manz; Tanya S Freedman; Chao Zhang; Kevan M Shokat; Arthur Weiss

doi:10.1038/ni.2772

Inhibition of the kinase Csk in thymocytes reveals a requirement for actin remodeling in the initiation of full TCR signaling

Nat Immunol. 2014 Feb;15(2):186-94. doi: 10.1038/ni.2772. Epub 2013 Dec 8.

Authors

Ying Xim Tan¹, Boryana N Manz¹, Tanya S Freedman¹, Chao Zhang², Kevan M Shokat³, Arthur Weiss⁴

Affiliations

¹ Rosalind Russell-Ephraim P. Engleman Medical Research Center for Arthritis, Division of Rheumatology, Department of Medicine, University of California, San Francisco, California, USA.
² Department of Chemistry, University of Southern California, California, USA.
³ 1] Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA. [2] Howard Hughes Medical Institute, Chevy Chase, Maryland, USA.
⁴ 1] Rosalind Russell-Ephraim P. Engleman Medical Research Center for Arthritis, Division of Rheumatology, Department of Medicine, University of California, San Francisco, California, USA. [2] Howard Hughes Medical Institute, Chevy Chase, Maryland, USA. [3] Department of Microbiology and Immunology, University of California, San Francisco, California, USA.

PMID: 24317039
PMCID: PMC3946925
DOI: 10.1038/ni.2772

Abstract

Signaling via the T cell antigen receptor (TCR) is initiated by Src-family kinases (SFKs). To understand how the kinase Csk, a negative regulator of SFKs, controls the basal state and the initiation of TCR signaling, we generated mice that express a Csk variant sensitive to an analog of the common kinase inhibitor PP1 (Csk(AS)). Inhibition of Csk(AS) in thymocytes, without engagement of the TCR, induced potent activation of SFKs and proximal TCR signaling up to phospholipase C-γ1 (PLC-γ1). Unexpectedly, increases in inositol phosphates, intracellular calcium and phosphorylation of the kinase Erk were impaired. Altering the actin cytoskeleton pharmacologically or providing costimulation via CD28 'rescued' those defects. Thus, Csk has a critical role in preventing TCR signaling. However, our studies also revealed a requirement for actin remodeling, initiated by costimulation, for full TCR signaling.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Actins / metabolism*
Animals
CD28 Antigens / immunology
CSK Tyrosine-Protein Kinase
Cells, Cultured
Cytochalasin D / administration & dosage
Cytoskeleton / drug effects
Cytoskeleton / metabolism*
Mice
Mice, Inbred C57BL
Mice, Transgenic
Mutant Proteins / genetics
Mutant Proteins / metabolism*
Polymerization / drug effects
Protein Engineering
Pyrazoles / administration & dosage
Pyrimidines / administration & dosage
Receptors, Antigen, T-Cell / immunology
Receptors, Antigen, T-Cell / metabolism*
Signal Transduction / drug effects
Signal Transduction / genetics
Thymocytes / drug effects
Thymocytes / immunology*
src-Family Kinases / antagonists & inhibitors
src-Family Kinases / genetics
src-Family Kinases / metabolism*

Substances

4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine
Actins
CD28 Antigens
Mutant Proteins
Pyrazoles
Pyrimidines
Receptors, Antigen, T-Cell
Cytochalasin D
CSK Tyrosine-Protein Kinase
src-Family Kinases

Abstract

Publication types

MeSH terms

Substances

Grants and funding