Cell surface receptor that regulates diverse cellular processes including cell proliferation, differentiation, migration, and apoptosis (PubMed:12958365, PubMed:19416857). Initiates BMP, inhibin, and TGF-beta signaling pathways by interacting with different ligands including TGFB1, BMP2, BMP5, BMP7 or GDF5 (PubMed:18184661). Alternatively, acts as a cell surface coreceptor for BMP ligands, serving to enhance ligand binding by differentially regulating BMPR1A/ALK3 and BMPR1B/ALK6 receptor trafficking (PubMed:19726563). Promotes epithelial cell adhesion, focal adhesion formation and integrin signaling during epithelial cell spreading on fibronectin (PubMed:22562249). By interacting with the scaffolding protein beta- arrestin2/ARRB2, regulates migration or actin cytoskeleton and promotes the activation of CDC42 as well as the inhibition of NF-kappa-B (PubMed:19416857, PubMed:19325136). In gonadotrope cells, acts as an inhibin A coreceptor and regulates follicle-stimulating hormone (FSH) levels and female fertility (By similarity). Plays a role in the inhibition of directed and random cell migration in epithelial cells by altering the actin cytoskeletal organization (PubMed:19416857). Participates in epithelial-mesenchymal transformation (EMT) upon binding to BMP2 or TGFB2, by activating the PAR6/SMURF1/RHOA pathway (By similarity). {ECO:0000250|UniProtKB:P26342, ECO:0000269|PubMed:18184661, ECO:0000269|PubMed:19325136, ECO:0000269|PubMed:19416857, ECO:0000269|PubMed:19726563, ECO:0000269|PubMed:22562249, ECO:0000269|PubMed:34910520}. (Microbial infection) May act as a receptor for human cytomegalovirus in different cell types by interacting with HCMV trimer composed of GO, GH and GL. . This is the function of Ensembl gene identifier ENSG00000069702 (TGFBR3, transforming growth factor beta receptor 3).