TY - JOUR
T1 - Inactivation of activin-dependent transcription by kinase-deficient activin receptors
AU - Tsuchida, Kunihiro
AU - Vaughan, Joan M.
AU - Wiater, Ezra
AU - Gaddy-Kurtens, Dana
AU - Vale, Wylie W.
PY - 1995/12
Y1 - 1995/12
N2 - Activin, a member of the transforming growth factor-beta superfamily, binds to two classes of cell surface receptors. These receptors, designated type I and type II, are structurally related members of transmembrane serine kinase superfamily. Antibodies specific for either type I or type II activin receptor can coprecipitate complexes containing both affinity-labeled receptors from activin-responsive cells. Two type I receptors show cell-specific expression and associate with the ligand-binding, type II receptors. To investigate the roles of the cytoplasmic receptor domains in signaling through a heteromeric ligand receptor complex, we have made kinase-deficient activin receptors and correlated their losses in kinase activity with inhibitory effects on an activin-dependent transcriptional response in activin-responsive cell lines. Wild-type activin type II receptors phosphorylate activin type I receptors in transfected COS cells. In contrast, kinase-deficient activin type II receptors fail to phosphorylate type I receptors in transfected COS cells and act as dominant negative mutants to block activin-induced transcriptional activity in both Chinese hamster ovary and K562 (human erythroleukemia) cells. Kinase-deficient activin type IB receptors also block activin-induced transcriptional activity in both Chinese hamster ovary and K562 cells, whereas kinase-deficient activin type I receptors have no effect in either cell line. These results indicate that kinase activities of both type II and type I receptors are required for activin signaling, and that the two type I receptors, which are expressed in a tissue-specific manner, are functionally distinct.
AB - Activin, a member of the transforming growth factor-beta superfamily, binds to two classes of cell surface receptors. These receptors, designated type I and type II, are structurally related members of transmembrane serine kinase superfamily. Antibodies specific for either type I or type II activin receptor can coprecipitate complexes containing both affinity-labeled receptors from activin-responsive cells. Two type I receptors show cell-specific expression and associate with the ligand-binding, type II receptors. To investigate the roles of the cytoplasmic receptor domains in signaling through a heteromeric ligand receptor complex, we have made kinase-deficient activin receptors and correlated their losses in kinase activity with inhibitory effects on an activin-dependent transcriptional response in activin-responsive cell lines. Wild-type activin type II receptors phosphorylate activin type I receptors in transfected COS cells. In contrast, kinase-deficient activin type II receptors fail to phosphorylate type I receptors in transfected COS cells and act as dominant negative mutants to block activin-induced transcriptional activity in both Chinese hamster ovary and K562 (human erythroleukemia) cells. Kinase-deficient activin type IB receptors also block activin-induced transcriptional activity in both Chinese hamster ovary and K562 cells, whereas kinase-deficient activin type I receptors have no effect in either cell line. These results indicate that kinase activities of both type II and type I receptors are required for activin signaling, and that the two type I receptors, which are expressed in a tissue-specific manner, are functionally distinct.
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U2 - 10.1210/endo.136.12.7588300
DO - 10.1210/endo.136.12.7588300
M3 - Article
C2 - 7588300
AN - SCOPUS:0028807860
VL - 136
SP - 5493
EP - 5503
JO - Endocrinology
JF - Endocrinology
SN - 0013-7227
IS - 12
ER -