SDCBP
Function
Multifunctional adapter protein involved in diverse array of functions including trafficking of transmembrane proteins, neuro and immunomodulation, exosome biogenesis, and tumorigenesis (PubMed:26291527). Positively regulates TGFB1-mediated SMAD2/3 activation and TGFB1-induced epithelial-to-mesenchymal transition (EMT) and cell migration in various cell types. May increase TGFB1 signaling by enhancing cell-surface expression of TGFR1 by preventing the interaction between TGFR1 and CAV1 and subsequent CAV1-dependent internalization and degradation of TGFR1 (PubMed:25893292). In concert with SDC1/4 and PDCD6IP, regulates exosome biogenesis (PubMed:22660413). Regulates migration, growth, proliferation, and cell cycle progression in a variety of cancer types (PubMed:26539120). In adherens junctions may function to couple syndecans to cytoskeletal proteins or signaling components. Seems to couple transcription factor SOX4 to the IL-5 receptor (IL5RA) (PubMed:11498591). May also play a role in vesicular trafficking (PubMed:11179419). Seems to be required for the targeting of TGFA to the cell surface in the early secretory pathway (PubMed:10230395).
Post-translational modifications
Phosphorylated on tyrosine residues.
Tissue Specificity
Expressed in lung cancers, including adenocarcinoma, squamous cell carcinoma and small-cell carcinoma (at protein level) (PubMed:25893292). Widely expressed. Expressed in fetal kidney, liver, lung and brain. In adult highest expression in heart and placenta.
Cellular localization
- Cell junction
- Focal adhesion
- Cell junction
- Adherens junction
- Cell membrane
- Peripheral membrane protein
- Endoplasmic reticulum membrane
- Peripheral membrane protein
- Nucleus
- Melanosome
- Cytoplasm
- Cytosol
- Cytoplasm
- Cytoskeleton
- Secreted
- Extracellular exosome
- Membrane raft
- Mainly membrane-associated. Localized to adherens junctions, focal adhesions and endoplasmic reticulum. Colocalized with actin stress fibers. Also found in the nucleus. Identified by mass spectrometry in melanosome fractions from stage I to stage IV. Associated to the plasma membrane in the presence of FZD7 and phosphatidylinositol 4,5-bisphosphate (PIP2) (PubMed:27386966).
Alternative names
MDA9, SYCL, SDCBP, Syntenin-1, Melanoma differentiation-associated protein 9, Pro-TGF-alpha cytoplasmic domain-interacting protein 18, Scaffold protein Pbp1, Syndecan-binding protein 1, MDA-9, TACIP18