First Author | Tu CF | Year | 2008 |
Journal | J Biol Chem | Volume | 283 |
Issue | 18 | Pages | 12478-88 |
PubMed ID | 18303018 | Mgi Jnum | J:136534 |
Mgi Id | MGI:3796459 | Doi | 10.1074/jbc.M705872200 |
Citation | Tu CF, et al. (2008) Domain and functional analysis of a novel platelet-endothelial cell surface protein, SCUBE1. J Biol Chem 283(18):12478-88 |
abstractText | SCUBE1 (signal peptide-CUB-EGF domain-containing protein 1) is a novel, secreted, cell surface glycoprotein expressed during early embryogenesis and found in platelet and endothelial cells. This protein is composed of an N-terminal signal peptide sequence followed by nine tandemly arranged epidermal growth factor (EGF)-like repeats, a spacer region, three cysteine-rich repeat motifs, and one CUB domain at the C terminus. However, little is known about its domain and biological function. Here, we generated a comprehensive panel of domain deletion constructs and a new genetic mouse model with targeted disruption of Scube1 (Scube1(Delta cub/Delta cub)) to investigate the domain function and biological significance. A number of cell-based assays were utilized to define the critical role of the spacer region for membrane association and establish that the EGF-like repeats 7-9 are sufficient for the formation of SCUBE1-mediated homophilic adhesions in a calcium-dependent fashion. Biochemical and molecular analyses showed that the C-terminal cysteine-rich motifs and CUB domain could directly bind and antagonize the bone morphogenetic protein activity. Furthermore, genetic ablation of this C-terminal region resulted in brain malformation in the Scube1(Delta cub/Delta cub) embryos. Together, our results support the dual roles of SCUBE1 on brain morphogenesis and cell-cell adhesions through its distinct domain function. |