- Tetraspanin
-
Tetraspanin family 
Tetraspanins have four transmembrane domains, two extracellular loops and contain a series of highly conserved amino acid residues. Identifiers Symbol Tetraspannin Pfam PF00335 Pfam clan CL0347 InterPro IPR000301 PROSITE PDOC00371 SCOP 1iv5 CDD cd03127 Available protein structures: Pfam structures PDB RCSB PDB; PDBe PDBsum structure summary Tetraspanins are a family of membrane proteins found in all multicellular eukaryotes.
Tetraspanins, also called tetraspans or the transmembrane 4 superfamily (TM4SF), have four transmembrane domains, intracellular N- and C-termini and two extracellular domains, one short (called the small extracellular domain or loop, SED/SEL or EC1) and one longer, typically 100 amino acid residues (the large extracellular domain/loop, LED/LEL or EC2). Although several protein families have four transmembrane domains, tetraspanins are defined by conserved domains listed in the Protein Families database under pfam00335.12.[1] The key features are four or more cysteine residues in the EC2 domain, with two in a highly conserved 'CCG' motif.
Research into this field is relatively recent (less than 20 years) and therefore there is much to learn about the function of specific tetraspanins. Generally, tetraspanins are often thought to act as scaffolding proteins, anchoring multiple proteins to one area of the cell membrane.[2]
Tetraspanins are highly conserved between species. Some tetraspanins can have N-linked glycosylations on the long extracellular loop (LEL, EC2) and palmitoylations at a CXXC motif in their transmembrane region.[3]
There are 34 tetraspanins in mammals, 33 of which have also been identified in humans. Tetraspanins display numerous properties that indicate their physiological importance in cell adhesion, motility, activation and proliferation, as well as their contribution to pathological conditions such as metastasis or viral infection.
A role for tetraspanins in platelets was demonstrated by the bleeding phenotypes of CD151- and TSSC6-deficient mice, which exhibit impaired "outside-in" signalling through αIIbβ3, the major platelet integrin. it is hypothesized that tetraspanins interact with and regulate other platelet receptors.[4]
Contents
List of human tetraspanins
Protein Gene Aliases TSPAN1 TSPAN1 TSP-1 TSPAN2 TSPAN2 TSP-2 TSPAN3 TSPAN3 TSP-3 TSPAN4 TSPAN4 TSP-4, NAG-2 TSPAN5 TSPAN5 TSP-5 TSPAN6 TSPAN6 TSP-6 TSPAN7 TSPAN5 CD231/TALLA-1/A15 TSPAN8 TSPAN8 CO-029 TSPAN9 TSPAN9 NET-5 TSPAN10 TSPAN10 OCULOSPANIN TSPAN11 TSPAN11 CD151-like TSPAN12 TSPAN12 NET-2 TSPAN13 TSPAN13 NET-6 TSPAN14 TSPAN14 TSPAN15 TSPAN15 NET-7 TSPAN16 TSPAN16 TM4-B TSPAN17 TSPAN17 TSPAN18 TSPAN18 TSPAN19 TSPAN19 TSPAN20 UPK1B UP1b, UPK1B TSPAN21 TSPAN21 UP1a, UPK1A TSPAN22 PRPH2 RDS, PRPH2 TSPAN23 TSPAN23 ROM1 TSPAN24 CD151 CD151 TSPAN25 CD53 CD53 TSPAN26 CD37 CD37 TSPAN27 CD82 CD82 TSPAN28 CD81 CD81 TSPAN29 CD9 CD9 TSPAN30 CD63 CD63 TSPAN31 TSPAN31 SAS TSPAN32 TSPAN32 TSSC6 TSPAN33 TSPAN33 TSPAN34 TSPAN34 See also
Relevance to parasite vaccines
The schistosome worms make two tetraspanins: TSP-1 and TSP-2. TSP-2 antibodies are found in some people who seem to have immunity to schistosome infection (Schistosomiasis).[5]
External links
References
- ^ Pfam
- ^ Hemler ME (2005). "Tetraspanin functions and associated microdomains". Nat. Rev. Mol. Cell Biol. 6 (10): 801–11. doi:10.1038/nrm1736. PMID 16314869.
- ^ Wright MD, Tomlinson MG (1994). "The ins and outs of the transmembrane 4 superfamily". Immunol. Today 15 (12): 588–94. doi:10.1016/0167-5699(94)90222-4. PMID 7531445.
- ^ Goschnick MW, Lau LM, Wee JL, Liu YS, Hogarth PM, Robb LM, Hickey MJ, Wright MD, Jackson DE (2006). "Impaired "outside-in" integrin alphaIIbbeta3 signaling and thrombus stability in TSSC6-deficient mice". Blood 108 (6): 1911–8. doi:10.1182/blood-2006-02-004267. PMID 16720835.
- ^ Scientific American May 2008, referring to McManus & Loukas Clinical Microbiology reviews V21,N1,p225-242 (Jan 2008)
Arrestin Membrane-spanning 4A Myelin Pulmonary surfactant Tetraspanin TSPAN1 · TSPAN2 · TSPAN3 · TSPAN4 · TSPAN5 · TSPAN6 · TSPAN7 · TSPAN8 · TSPAN9 · TSPAN10 · TSPAN11 · TSPAN12 · TSPAN13 · TSPAN14 · TSPAN15 · TSPAN16 · TSPAN17 · TSPAN18 · TSPAN19 · TSPAN20 · TSPAN21 · TSPAN22 · TSPAN23 · TSPAN24 · TSPAN25 · TSPAN26 · TSPAN27 · TSPAN28 · TSPAN29 · TSPAN30 · TSPAN31 · TSPAN32 · TSPAN33 · TSPAN34Other/ungrouped Calnexin · LDL-receptor-related protein associated protein · Neurofibromin 2 · Presenilin (PSEN1, PSEN2) · HFE · Phospholipid transfer proteins · Dysferlin · STRC · OTOFCategories:- Membrane biology
- Integral membrane proteins
- Protein domains
- Immunology
Wikimedia Foundation. 2010.
