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Phosphorylation of Ser165 in TGF‐beta type I receptor modulates TGF‐beta1‐induced cellular responses.
Author(s) -
Souchelnytskyi S.,
Dijke P.,
Miyazono K.,
Heldin C. H.
Publication year - 1996
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1996.tb01013.x
Subject(s) - cancer , biology , transforming growth factor beta , library science , cancer research , receptor , genetics , computer science
Transforming growth factor‐beta (TGF‐beta) signals via an oligomeric complex of two serine/threonine kinase receptors denoted TGF‐beta type I receptor (TbetaR‐I) and type II receptor (TbetaR‐II). We investigated the in vivo phosphorylation sites in TbetaR‐I and TbetaR‐II after complex formation. Phosphorylation of TbetaR‐II was observed at residues in the C‐terminus (Ser549 and Ser551) and at residues in the juxtamembrane domain (Ser223, Ser226 and Ser227). TGF‐beta1 induced in vivo phosphorylation of serine and threonine residues in the juxtamembrane domain of TbetaR‐I in a region rich in glycine, serine and threonine residues (GS domain; Thr185, Thr186, Ser187, Ser189 and Ser191), and more N‐terminal of this region (Ser165). Phosphorylation in the GS domain has been shown previously to be involved in activation of the TbetaR‐I kinase. We show here that phosphorylation of TbetaR‐I at Ser165 is involved in modulation of TGF‐beta1 signaling. Mutations of Ser165 in TbetaR‐I led to an increase in TGF‐beta1‐mediated growth inhibition and extracellular matrix formation, but, in contrast, to decreased TGF‐beta1‐induced apoptosis. A transcriptional activation signal was not affected. Mutations of Ser165 changed the phosphorylation pattern of TbetaR‐I. These observations suggest that TGF‐beta receptor signaling specificity is modulated by phosphorylation of Ser165 of TbetaR‐I.