CD81
CD81 (CD81 molecule, also known as TAPA-1, TSPAN28 and S5.7) is a cell-surface glycoprotein of the tetraspanin family. It complexes with integrins, may contribute to signal transduction and is required for Plasmodium falciparum infection of hepatocytes. Browse Assay Genie's current range of CD81 research reagents below, or read on for the biology behind the target.
CD81 is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most members of this family are cell-surface proteins characterised by four hydrophobic domains, and they mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. CD81 is a cell-surface glycoprotein that is known to complex with integrins, and it may be involved in signal transduction. It appears to promote muscle cell fusion and support myotube maintenance.
In the context of infection, UniProt annotates CD81 as specifically required for Plasmodium falciparum infectivity of hepatocytes. It controls sporozoite entry into hepatocytes via the parasitophorous vacuole and the subsequent differentiation of the parasite to exoerythrocytic forms. The protein is found at the cell membrane, including the basolateral cell membrane.
The human CD81 gene is classed by HGNC within the CD molecules, the tetraspanin family and the gamete adhesion and fusion factors. Mouse and rat both carry a Cd81 ortholog. The gene lies in a tumour-suppressor gene region and is therefore considered a candidate gene for malignancies. Two transcript variants encoding different isoforms have been described. Earlier nomenclature referred to the product as the CD81 antigen, the target of antiproliferative antibody 1, and the TAPA-1 alias reflects that history.
CD81 complexes with integrins, making it a useful subject for studying how tetraspanins organise cell-surface assemblies.
CD81 is required for P. falciparum sporozoite entry into hepatocytes and parasite differentiation, linking it to liver-stage infection research.
CD81 appears to promote muscle cell fusion and support myotube maintenance, relevant to studies of myogenesis.
Tetraspanins regulate cell activation, growth and motility, and the CD81 gene sits in a tumour-suppressor region, making it a candidate in malignancy studies.
CD81 is a tetraspanin cell-surface glycoprotein that complexes with integrins and may be involved in signal transduction. It appears to promote muscle cell fusion and support myotube maintenance, and it is required for Plasmodium falciparum sporozoite entry into hepatocytes.
CD81 is also called TAPA-1, TSPAN28 and S5.7, and was formerly named CD81 antigen (target of antiproliferative antibody 1). Two transcript variants of the CD81 gene encode different isoforms, so literature may describe more than one form.
Mouse and rat both have a Cd81 ortholog, so the protein can be studied in rodent models; check the datasheet of any product for its validated reactivity. The gene lies in a tumour-suppressor region and is a candidate gene for malignancies, and the protein is needed for liver-stage malaria infection.
Other CD molecules and cell-surface proteins involved in adhesion and signalling, with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P60033; product specifications from Assay Genie datasheets.