Tetraspanin 9 (TSPAN9)

TSPAN9 is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains. The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. Alternatively spliced transcripts encoding the same protein have been identified.

By searching an EST database for tetraspanin-like sequences, followed by 5-prime RACE of a HeLa cell cDNA library, Serru et al. (2000) cloned TSPAN9, which they called NET5. The deduced 239-amino acid protein contains 4 transmembrane segments and other characteristics of a tetraspanin. RT-PCR detected TSPAN9 expression in all human cell lines examined.