TY - JOUR
T1 - Syk tyrosine kinase is required for immunoreceptor tyrosine activation motif-dependent actin assembly
AU - Cox, Dianne
AU - Chang, Peter
AU - Kurosaki, Tomohiro
AU - Greenberg, Steven
PY - 1996
Y1 - 1996
N2 - Clustering of several multisubunit receptors on hematopoetic cells results in a signaling cascade involving the phosphorylation of immunoreceptor tyrosine activation motifs, or 'ITAMs,' and actin polymerization. Recent experiments indicate that direct clustering of the ITAM-binding protein, p72(syk) (Syk), is capable of transmitting a phagocytic signal in COS cells (Greenberg, S., Chang, P., Wang, D., Xavier, R., and Seed, B. (1996) Proc. Natl. Acad. Sci. U.S.A. 93, 1103-1107). However, the possibility of redundant signaling pathways makes it difficult to test the requirement for Syk in ITAM-dependent actin polymerization in hematopoetic cells. We developed a model system to study ITAM-dependent actin assembly. DT40 lymphocytes were transfected with fusion proteins encoding the transmembrane and cytosolic domains of the ITAM-containing γ subunit of Fc receptors. Clustering the γ-containing fusion proteins with IgG-coated erythrocytes triggered submembranous actin assembly. This response depended on an intact ITAM, was absent in cell lines that had been engineered to lack Syk, and was augmented in cell lines that stably overexpressed Syk. These experiments demonstrate an absolute requirement for Syk tyrosine kinase in ITAM-dependent actin assembly in transfected lymphocytes.
AB - Clustering of several multisubunit receptors on hematopoetic cells results in a signaling cascade involving the phosphorylation of immunoreceptor tyrosine activation motifs, or 'ITAMs,' and actin polymerization. Recent experiments indicate that direct clustering of the ITAM-binding protein, p72(syk) (Syk), is capable of transmitting a phagocytic signal in COS cells (Greenberg, S., Chang, P., Wang, D., Xavier, R., and Seed, B. (1996) Proc. Natl. Acad. Sci. U.S.A. 93, 1103-1107). However, the possibility of redundant signaling pathways makes it difficult to test the requirement for Syk in ITAM-dependent actin polymerization in hematopoetic cells. We developed a model system to study ITAM-dependent actin assembly. DT40 lymphocytes were transfected with fusion proteins encoding the transmembrane and cytosolic domains of the ITAM-containing γ subunit of Fc receptors. Clustering the γ-containing fusion proteins with IgG-coated erythrocytes triggered submembranous actin assembly. This response depended on an intact ITAM, was absent in cell lines that had been engineered to lack Syk, and was augmented in cell lines that stably overexpressed Syk. These experiments demonstrate an absolute requirement for Syk tyrosine kinase in ITAM-dependent actin assembly in transfected lymphocytes.
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U2 - 10.1074/jbc.271.28.16597
DO - 10.1074/jbc.271.28.16597
M3 - Article
C2 - 8663235
AN - SCOPUS:0030014646
SN - 0021-9258
VL - 271
SP - 16597
EP - 16602
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 28
ER -