TLR 3

Toll-like receptor 3
The structure of TLR3 covered with sugars
Available structures: 1ziw, 2a0z
Identifiers
Symbol(s)	TLR3; CD283
External IDs	OMIM: 603029 MGI: 2156367 Homologene: 20696
Gene Ontology Molecular Function: • double-stranded RNA binding • transmembrane receptor activity • protein binding Cellular Component: • integral to plasma membrane • membrane Biological Process: • inflammatory response • hyperosmotic response • signal transduction • activation of NF-kappaB-inducing kinase • detection of virus • defense response to bacterium • positive regulation of I-kappaB kinase/NF-kappaB cascade • positive regulation of interferon-gamma biosynthetic process • innate immune response • positive regulation of interferon-alpha biosynthetic process • positive regulation of interferon-beta biosynthetic process • negative regulation of osteoclast differentiation • positive regulation of JNK cascade
RNA expression pattern
Additional recommended knowledge Daily Visual Balance Check Weighing the right way Essential Laboratory Skills Guide More reference expression data
Orthologs
	Human	Mouse
Entrez	7098	142980
Ensembl	ENSG00000164342	ENSMUSG00000031639
Uniprot	O15455	Q3TM31
Refseq	NM_003265 (mRNA) NP_003256 (protein)	NM_126166 (mRNA) NP_569054 (protein)
Location	Chr 4: 187.23 - 187.24 Mb	Chr 8: 46.89 - 46.91 Mb
Pubmed search	[1]	[2]

TLR 3 is a member of the Toll-like receptor family of pattern recognition receptors of the innate immune system. Discovered in 2001,^[1] TLR3 recognizes double-stranded RNA, a form of genetic information carried by some viruses such as influenza. Upon recognition, TLR 3 induces the activation of NF-kB to increase production of type I interferons which signal other cells to increase their antiviral defenses. Double-stranded RNA is also recognised by the cytoplasmic receptors RIG-I and MDA-5.

Structure

The structure of TLR3 was reported in June 2005 by researchers at The Scripps Research Institute.^[2] TLR3 forms a large horseshoe shape that contacts with a neighboring horseshoe, forming a "dimer" of two horseshoes. Much of the TLR3 protein surface is covered with sugar molecules, making it a glycoprotein, but on one face (including the interface between the two horseshoes), there is a large sugar-free surface. This surface also contains two distinct patches rich in positively-charged amino acids, which may be a binding site for negatively-charged double-stranded RNA.

Despite being a glycoprotein, TLR3 crystallises readily - a prerequisite for structural analysis by x-ray crystallography.

References

Further reading