Key component of innate and adaptive immunity. TLRs (Toll-like receptors) control host immune response against pathogens through recognition of molecular patterns specific to microorganisms. TLR9 is a nucleotide-sensing TLR which is activated by unmethylated cytidine-phosphate-guanosine (CpG) dinucleotides. Acts via MYD88 and TRAF6, leading to NF-kappa-B activation, cytokine secretion and the inflammatory response. Controls lymphocyte response to Helicobacter infection. Interacts with MYD88 via their respective TIR domains. Interacts (via transmembrane domain) with UNC93B1. Interacts with CD300LH; the interaction may promote full activation of TLR9-triggered innate responses. Interacts with BTK. Interacts with CNPY3 and HSP90B1; this interaction is required for proper folding in the endoplasmic reticulum. Highly expressed in spleen, lymph node, tonsil and peripheral blood leukocytes, especially in plasmacytoid pre- dendritic cells. Levels are much lower in monocytes and CD11c+ immature dendritic cells. Also detected in lung and liver. Belongs to the Toll-like receptor family. 5 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Membrane protein, integral; Receptor, misc.