CXADR
Description
The CXADR (CXADR Ig-like cell adhesion molecule) is a protein-coding gene located on chromosome 21.
The CXADR gene encodes the Coxsackievirus and adenovirus receptor (CAR) protein, a type I membrane receptor for group B coxsackie viruses and subgroup C adenoviruses. CAR is expressed in various tissues, including heart, brain, and epithelial and endothelial cells. In the heart, CAR is located in intercalated disc structures, crucial for the electrical and mechanical coupling of cardiomyocytes. CAR plays a significant role in the development of myocarditis, dilated cardiomyopathy, and arrhythmia susceptibility following myocardial infarction or ischemia. Additionally, a CAR isoform (CAR-SIV) has been identified in pancreatic beta cells, potentially residing within insulin secreting granules and contributing to virus infection of these cells. The human CAR protein has a theoretical molecular weight of 40.0 kDa and is composed of 365 amino acids. The CXADR gene is located on chromosome 21. Alternative splicing produces at least two splice variants, hCAR1 and hCAR2, each composed of at least 7 exons.
CXADR is a crucial component of the epithelial apical junction complex, acting as a homophilic cell adhesion molecule and ensuring tight junction integrity. It facilitates leukocyte migration across epithelial barriers by interacting with JAML, a transmembrane protein found on leukocyte plasma membranes. This interaction also triggers the activation of gamma-delta T-cells, a specific T-cell subpopulation residing in epithelial tissues and playing a role in maintaining tissue homeostasis and repair. When CXADR binds to JAML on epithelial cells, it initiates downstream signaling events in gamma-delta T-cells through PI3-kinase and MAP kinases, leading to cell proliferation and the production of cytokines and growth factors. These factors, in turn, stimulate the repair of epithelial tissues.
CXADR is also known as CAR, CAR4/6, HCAR.
