L-Selectin (CD62L)

L-Selectin (also known as Leukocyte Selectin), a member of the Selectin family, is a cell surface glycoprotein expressed constitutively on a wide variety of leukocytes. Two forms of L‑Selectin have been reported, apparently arising as a result of post-translational modifications. The lymphocyte form shows an apparent molecular weight of 74 kDa, while the neutrophil form is 90 - 100 kDa. Human and mouse L‑Selectin share 76% amino acid (aa) sequence homology. L‑Selectin plays a role in the migration of lymphocytes into peripheral lymph nodes and sites of chronic inflammation, and of neutrophils into acute inflammatory sites. Acting in cooperation with P-Selectin and E-Selectin, L‑Selectin mediates the initial interaction of circulating leukocytes with endothelial cells that produces a characteristic "rolling" of the leukocytes on the endothelium. This initial interaction, also involving ICAM-1 and VCAM-1, leads eventually to extravasation of the white blood cell through the blood vessel wall into the extracellular matrix tissue.