TLR5

Toll-like receptor 5, also known as TLR5, is a is_associated_with::protein which in humans is encoded by the TLR5 is_associated_with::gene. It is a member of the is_associated_with::toll-like receptor (TLR) family.

Function
The TLR family plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from is_associated_with::Drosophila to humans and share structural and functional similarities. They recognize pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity. The various TLRs exhibit different patterns of expression. TLR5 is expressed on both immune and non-immune cells. TLR5 recognizes bacterial is_associated_with::flagellin, a principal component of bacterial flagella and a virulence factor. The activation of this receptor mobilizes the nuclear factor is_associated_with::NF-κB and stimulates is_associated_with::tumor necrosis factor-alpha production.

TLR5 recognizes flagellin, which is the protein monomer that makes up the filament of bacterial flagella, found on nearly all motile bacteria. There are highly conserved regions in the flagellin protein among all bacteria, facilitating the recognition of flagellin by a germ-line encoded receptor such as TLR5.