- Peptide (C)GRVRTYQFDSFLESTR, corresponding to amino acid residues 97-112 of mouse BAI1 (Accession Q3UHD1). Extracellular, N-terminus.
- Human THP-1 monocytic leukemia cells 2.5 µg antibody per 0.5x106 cells. Mouse J774 macrophage cells 5 µg antibody per 0.5x106 cells.
- Cell surface detection of BAI1 in live intact human THP-1 monocytic leukemia cells:___ Cells.
___ Cells + Rabbit IgG isotype control-FITC.
___ Cells + Anti-BAI1 (extracellular)-FITC Antibody (#ABR-021-F), (2.5 µg antibody/0.5x106 cells).
The three members of the brain angiogenesis inhibitor (BaI1-3) are receptors belonging to the adhesion subfamily of G-protein coupled receptor superfamily. Like all members of GPCRs, all three BaIs have seven transmembrane domains, an intracellular C-terminal tail and extracellular N-terminus. Like other adhesion members, the N-terminus is quite large1,2. Many domains are localized to the N-terminus; various glycosylations sites are present, there is a GPCR proteolysis site, a putative hormone binding domain and thrombospondin type 1 repeats which regulate the anti-angiogenic activity of thrombospondin-12,3. The C-terminal tail interacts with PDZ-domain proteins. Unique to BaI1 is a proline-rich domain required for interacting with Src homology domains and WW domain proteins2,4.
Like most adhesion GPCRs, BaI also undergo proteolysis at the N-terminus at a highly rich cystein domain2. Following autocleavage, the N-terminal fragment remains associated to the receptor. In BaI1, proteolysis yields a partly secreted 120 kDa. fragment (vasculostatin-120) or a 40 kDa. fragment both having antiangiogenic effects2,5.
At the mRNA level, all BaIs are expressed in fetal and adult human brain2,6. BaI2 is detected in the human heart and skeletal muscle. BaI3 is expressed in the human heart, testis and small intestine. In mouse, both BaI2 and BaI3 are restricted to the brain2.
These receptors are implicated in various diseases and disorders such as primary glioma, pulmonary adenocarcinomas, gastric and colorectal cancers2,6,7.