Background:

VCAM-1, also known as CD106, is an immunoglobulin (Ig)-like adhesion molecule that is mainly expressed in endothelial cells and other cell types including macrophages, dendritic cells, neurons, smooth muscle cells, fibroblasts, and oocytes. It plays a critical role in inflammation by recruiting leukocytes to acute and chronic inflammation sites. Alternatively-spliced forms are known to occur, but the most common form is a type I transmembrane protein with a 674 aa extracellular domain (ECD) that includes seven C2-type immunoglobulin domains, a 22 aa transmembrane segment, and a 19 amino acid (aa) cytoplasmic tail. Within the ECD, human VCAM-1 shares 75% and 76% aa sequence identity with the mouse and rat VCAM-1, respectively. VCAM-1 binds to leukocyte integrins alpha 4 beta 1 (VLA-4) and alpha 4 beta 7. During the inflammatory adhesion mechanism, activated integrins halt rolling leukocytes and attach them firmly to the vascular endothelium. The VCAM-1:VLA-4/ alpha 4 beta 7 interaction is also thought to be involved in the extravasation of white blood cells through the blood vessel wall to sites of inflammation. ELISA techniques have shown that detectable levels of soluble VCAM-1 are present in the biological fluids of apparently normal individuals, but elevated levels of serum VCAM-1 are indicative of future Atrial Fibrillation incident as well as liver disease. Tumor cells use overexpression of VCAM-1 as means of escaping immune surveillance.

Post-translational modifications：

Sialoglycoprotein.

Function:

Important in cell-cell recognition. Appears to function in leukocyte-endothelial cell adhesion. Interacts with the beta-1 integrin VLA4 on leukocytes, and mediates both adhesion and signal transduction. The VCAM1/VLA4 interaction may play a pathophysiologic role both in immune responses and in leukocyte emigration to sites of inflammation.