Plexin C1, also known as Virus-encoded semaphorin protein receptor (VESPR) and CD232, is a 210kD type I transmembrane glycoprotein in the C subfamily of the plexin family. Human Plexin C1 contains a 34aa signal sequence, a 910aa extracellular domain (ECD) with one Semadomain and two cysteinerich Metrelated sequences (MRS), a 21aa transmembrane domain and a 603aa cytoplasmic domain that includes features common to other plexins, including a phosphothreonine site. The mouse Plexin C1 ECD shares 85%, 78% and 65% aa identity with human, bovine and equine Plexin C1, respectively. A truncated rat Plexin C1 cDNA that encodes an apparently soluble form shares 93% aa identity with mouse Plexin C1 within aa 263932. Plexin C1 is widely expressed in neuronal and nonneuronal fetal and adult tissues. In neuronal development, its role is unclear. Semaphorin7a (Sema7a, CD108) binds Plexin C1 in vitro and the two show a similar expression pattern during rat neuronal development, but beta-1 integrins rather than Plexin C1 appear to mediate Sema7a effects on axon outgrowth. Plexin C1 does appear to play a role in partitioning of paraventricular and supraoptic neurons in the hypothalamus, as indicated by specific defects seen in mice deleted for Plexin C1 In the immune system, effects of Sema7a on T cellmediated inflammatory responses also appear to be mediated by beta-1 integrins rather than plexins. However, Plexin C1 may function to oppose the effect of beta-1 integrins, as it does on Sema7a- mediated spreading and dendrite formation in melanocytes Its expression is lost in melanoma metastasis, suggesting a role as a tumor suppressor Plexin C1 is the receptor for poxvirus (A39R protein) and herpes virus (AHVsema) semaphorin homologs, and mediates activation of monocytes and inhibition of dendritic cell and neutrophil phagocytosis and migration by A39R. Chinese Hamster Ovary cell line, CHO-derived, Ala35-Thr950, with a C-terminal 6-His tag. SDS-PAGE: 160-170kD, reducing conditions Activity: Measured by its binding ability in a functional ELISA. When recombinant mouse Plexin C1 is coated at 5ug/ml (100ul/well), recombinant mouse Semaphorin 7A/Fc Chimera binds with an apparent KD 5nM. Storage and Stability: Lyophilized and reconstituted products are stable for 6 months after receipt at -20C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
