The importance of Src homology 2 domain-containing leukocyte phosphoprotein of 76 kilodaltons sterile-alpha motif domain in thymic selection and T-cell activation.
The Src homology 2 domain-containing leukocyte phosphoprotein of 76 kilodaltons (SLP-76) is a cytosolic adaptor protein essential for thymocyte development and T-cell activation. It contains a sterile-alpha motif (SAM) domain, 3 phosphotyrosine motifs, a proline-rich region, and a Src homology 2 domain. Whereas the other domains have been extensively studied, the role of the SAM domain in SLP-76 function is not known. To understand the function of this domain, we generated SLP-76 knockin mice with the SAM domain deleted. Analysis of these mice showed that thymocyte development was partially blocked at the double-positive to single-positive transition. Positive and negative thymic selection was also impaired. In addition, we analyzed T-cell receptor (TCR)-mediated signaling in T cells from these mutant mice. TCR-mediated inositol 1,4,5-triphosphate production, calcium flux, and extracellular signal-regulated kinase activation were decreased, leading to defective interleukin-2 production and proliferation. Moreover, despite normal association between Gads and SLP-76, TCR-mediated formation of SLP-76 microclusters was impaired by the deletion of the SAM domain. Altogether, our data demonstrated that the SAM domain is indispensable for optimal SLP-76 signaling.
Shen
Shudan
S
Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
Lau
Jasmine
J
Zhu
Minghua
M
Zou
Jianwei
J
Fuller
Deirdre
D
Li
Qi-jing
QJ
Zhang
Weiguo
W
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000818:Animals; D001483:Base Sequence; D020013:Calcium Signaling; D002454:Cell Differentiation; D049109:Cell Proliferation; D017931:DNA Primers / Q000235:genetics; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D017434:Protein Structure, Tertiary; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D017384:Sequence Deletion; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
D048868:Adaptor Proteins, Signal Transducing; D017931:DNA Primers; D007376:Interleukin-2; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins; C092947:SLP-76 signal Transducing adaptor proteins