Open AccessCloning and characterization of a transmembrane serine kinase that acts as an activin type I receptor.
Author(s) -
Kunihiro Tsuchida,
Lawrence S. Mathews,
Wylie Vale
Publication year - 1993
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.90.23.11242
Subject(s) - acvr2b , activin receptor , activin type 2 receptors , biology , microbiology and biotechnology , tgf beta signaling pathway , transmembrane protein , receptor , biochemistry
Activin type II receptors are transmembrane protein-serine/threonine kinases. By using a reverse-transcription PCR assay to screen for protein kinase sequences, we isolated a cDNA clone, activin X1 receptor, from rat brain that encodes a 55-kDa transmembrane protein-serine kinase which is structurally related to other receptors in this kinase subfamily. The predicted protein consists of 509 amino acids, and the kinase domain shows 40% and 37% identity to the activin and transforming growth factor beta type II receptors, respectively. No activin-binding was observed when activin X1 receptor was expressed alone in COS-M6 cells; however, coexpression with type II activin receptors gave rise to a 68-kDa affinity-labeled complex in addition to the 85-kDa type II receptor complex. The size of this cross-linked band is consistent with the size of the type I activin receptor; furthermore, activin X1 receptor associated with type II receptors, as judged by coimmunoprecipitation with type II receptor antibodies. These data suggest that activin X1 receptor can serve as an activin type I receptor and that the diverse biological effects of activins may be mediated by a complex formed by the interaction of two transmembrane protein-serine kinases.