UNC93B1

Unc-93 homolog B1 (C. elegans), also known as UNC93B1, is a is_associated_with::protein which in humans is encoded by the UNC93B1 is_associated_with::gene.

Function
This gene encodes a protein with similarity to the is_associated_with::Caenorhabditis elegans is_associated_with::unc93 protein. The Unc93 protein is involved in the regulation or coordination of muscle contraction in the worm.

Molecular biology
The gene is located on long arm of chromosome 11 (11q13) on the minus (Crick) strand and was first identified in 2002. This protein is an intrinsic membrane protein that spans the membrane twelve times. It is found in the is_associated_with::endoplasmic reticulum and is highly conserved.

Clinical importance
Unc93B1 protein appears to be involved in the innate immune response. Defects in the protein predispose to hypersensitity to infections with is_associated_with::herpes simplex virus and mouse is_associated_with::cytomegalovirus. The mechanism is unclear but Unc93B1 is known to interact with the is_associated_with::toll-like receptors TLR3, TLR7 and is_associated_with::TLR9 and it appears to be involved in the trafficking of these receptors within the cell. Mutations in this gene lead to selective impairment of dsRNA-induced is_associated_with::interferon alpha/beta and interferon 1 lambda production.

The intracellular toll-like receptors have been shown to interact with UNC93B in is_associated_with::splenocytes and bone marrow-derived is_associated_with::dendritic cells. TLR3 and TLR9 bind to UNC93B via their transmembrane domains. Introduction of the point mutation H412R (is_associated_with::histidine to is_associated_with::arginine at amino acid 412: a single base transition - is_associated_with::adenosine to is_associated_with::guanine at base 1235) in UNC93B abolishes this interaction.