Fig. 1. Schematic representation of a generic tetraspanin. The CCG motif and the position of the last cysteine residue in the large extracellular loop are conserved in all tetraspanins. The PxxCC motif is found in >65% of tetraspanins. Encircled residues are found in > 60% of tetraspanins. Most tetraspanins (with the exception of CD81 and NET-2) have a consensus site for N-linked glycosylation in the large extracellular loop (LECL) (marked as ). Note that a glycosylation site for CD9 was mapped to the small extracellular loop.

* The N-terminal region of oculospanin contains 78 residues.

** The C-terminal regions of RDS-1, ROM-1 and NET-2 contain 63, 65 and 63 residues, respectively.