Sdc4
Function
Cell surface proteoglycan which regulates exosome biogenesis in concert with SDCBP and PDCD6IP.
Post-translational modifications
Shedding is enhanced by a number of factors such as heparanase, thrombin or EGF. Also by stress and wound healing. PMA-mediated shedding is inhibited by TIMP3.
O-glycosylated; contains both chondroitin sulfate and heparan sulfate. Ser-44, Ser-62 and Ser-64 can all be modified by either chondroitin sulfate or heparan sulfate, and the protein exists in forms that contain only chondroitin sulfate, only heparan sulfate and both chondroitin sulfate and heparan sulfate.
Sequence Similarities
Belongs to the syndecan proteoglycan family.
Tissue Specificity
Ubiquitous. Highest levels in liver, kidney and lung.
Cellular localization
- Membrane
- Single-pass type I membrane protein
- Secreted
- Shedding of the ectodomain produces a soluble form.
Alternative names
Syndecan-4, SYND4, Ryudocan core protein, Sdc4