Functional cleavage of the common cytokine receptor gamma chain (gammac) by calpain.
The small subunit of calpain, a calcium-dependent cysteine protease, was found to interact with the cytoplasmic domain of the common cytokine receptor gamma chain (gammac) in a yeast two-hybrid interaction trap assay. This interaction was functional as demonstrated by the ability of calpain to cleave in vitro-translated wild-type gammac, but not gammac containing a mutation in the PEST (proline, glutamate, serine, and threonine) sequence in its cytoplasmic domain, as well as by the ability of endogenous calpain to mediate cleavage of gammac in a calcium-dependent fashion. In T cell receptor-stimulated murine thymocytes, calpain inhibitors decreased cleavage of gammac. Moreover, in single positive CD4(+) thymocytes, not only did a calpain inhibitor augment CD3-induced proliferation, but antibodies to gammac blocked this effect. Finally, treatment of cells with ionomycin could inhibit interleukin 2-induced STAT protein activation, but this inhibition could be reversed by calpain inhibitors. Together, these data suggest that calpain-mediated cleavage of gammac represents a mechanism by which gammac-dependent signaling can be controlled.
Noguchi
M
M
Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Sarin
A
A
Aman
M J
MJ
Nakajima
H
H
Shores
E W
EW
Henkart
P A
PA
Leonard
W J
WJ
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D002154:Calpain / Q000378:metabolism*; D002478:Cells, Cultured; D017931:DNA Primers; D018698:Glutamic Acid; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D015759:Ionomycin / Q000494:pharmacology; D008213:Lymphocyte Activation; D046911:Macromolecular Substances; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D011392:Proline; D014176:Protein Biosynthesis; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000502:physiology; D018121:Receptors, Cytokine / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D012694:Serine; D015398:Signal Transduction; D013379:Substrate Specificity; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D013912:Threonine
D017931:DNA Primers; D007376:Interleukin-2; D046911:Macromolecular Substances; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D018121:Receptors, Cytokine; D011994:Recombinant Proteins; D013912:Threonine; D018698:Glutamic Acid; D012694:Serine; D015759:Ionomycin; D011392:Proline; D002154:Calpain