Addressin
Addressin also known as mucosal vascular addressin cell adhesion molecule 1 is a protein that in humans is encoded by the MADCAM1 gene.
Addressin is an extracellular protein of the endothelium of venules.
Addressins are the ligands to the homing receptors of lymphocytes. The task of these ligands and their receptors is to determine which tissue the lymphocyte will enter next. They carry carbohydrates in order to be recognized by L-selectin.Function
The protein encoded by this gene is an endothelial cell adhesion molecule that interacts preferentially with the leukocyte beta7 integrin LPAM-1, L-selectin, and VLA-4 on myeloid cells to direct leukocytes into mucosal and inflamed tissues. It is a member of the immunoglobulin superfamily and is similar to ICAM-1 and VCAM-1.
In terms of migration, MADCAM is selectively expressed on mucosal endothelial cells, driving memory T-cell re-circulation through mucosal tissues. In contrast, and indeed the main difference between the two molecules, ICAM molecules are involved with naive T-cell re-circulation. Whereas MADCAM is selectively expressed, ICAM is broadly expressed on inflamed endothelium.
