Physical and functional interactions between type I transforming growth factor beta receptors and Balpha, a WD-40 repeat subunit of phosphatase 2A.
We have previously shown that a WD-40 repeat protein, TRIP-1, associates with the type II transforming growth factor beta (TGF-beta) receptor. In this report, we show that another WD-40 repeat protein, the Balpha subunit of protein phosphatase 2A, associates with the cytoplasmic domain of type I TGF-beta receptors. This association depends on the kinase activity of the type I receptor, is increased by coexpression of the type II receptor, which is known to phosphorylate and activate the type I receptor, and allows the type I receptor to phosphorylate Balpha. Furthermore, Balpha enhances the growth inhibition activity of TGF-beta in a receptor-dependent manner. Because Balpha has been characterized as a regulator of phosphatase 2A activity, our observations suggest possible functional interactions between the TGF-beta receptor complex and the regulation of protein phosphatase 2A.
Griswold-Prenner
I
I
Department of Growth and Development, University of California at San Francisco, San Francisco, California 94143-0640, USA.
Kamibayashi
C
C
Maruoka
E M
EM
Mumby
M C
MC
Derynck
R
R
D016475:3T3 Cells; D030201:Activin Receptors, Type I; D000818:Animals; D002455:Cell Division / Q000502:physiology; D003432:Cross-Linking Reagents / Q000378:metabolism; D019925:Cyclin A / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D017930:Genes, Reporter; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D010749:Phosphoprotein Phosphatases / Q000737:chemistry*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D054648:Protein Phosphatase 2; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
D003432:Cross-Linking Reagents; D019925:Cyclin A; D008565:Membrane Proteins; D018125:Receptors, Transforming Growth Factor beta; D011993:Recombinant Fusion Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D030201:Activin Receptors, Type I; D000077293:Receptor, Transforming Growth Factor-beta Type I; D000077294:Receptor, Transforming Growth Factor-beta Type II; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2