MEP1B
Function
Membrane metallopeptidase that sheds many membrane-bound proteins. Exhibits a strong preference for acidic amino acids at the P1' position. Known substrates include: FGF19, VGFA, IL1B, IL18, procollagen I and III, E-cadherin, KLK7, gastrin, ADAM10, tenascin-C. The presence of several pro-inflammatory cytokine among substrates implicate MEP1B in inflammation. It is also involved in tissue remodeling due to its capability to degrade extracellular matrix components. Cleaves also the amyloid precursor protein/APP, thereby releasing neurotoxic amyloid beta peptides (PubMed:27180357).
Post-translational modifications
Phosphorylated by PKC at multiple sites of its cytoplasmic part. Phosphorylation dcreases activity at the cell surface, leading to diminished substrate cleavage.
N-glycosylated; contains high mannose and/or complex biantennary structures.
O-glycosylation protect the C-terminal region from proteolytic cleavage and diminish secretion, this seems to be specific to human.
Proteolytically activated by trypsin in the intestinal lumen and kallikrein-related peptidases in other tissues.
Tissue Specificity
The major site of expression is the brush border membrane of small intestinal and kidney epithelial cells.
Cellular localization
- Cell membrane
- Single-pass type I membrane protein
- Secreted
- Homodimers are essentially membrane bound but may also be shed from the surface by ADAM-10 and ADAM-17.
Alternative names
Meprin A subunit beta, Endopeptidase-2, Meprin B, N-benzoyl-L-tyrosyl-P-amino-benzoic acid hydrolase subunit beta, PABA peptide hydrolase, PPH beta, MEP1B