Open AccessL‐selectin: mechanisms and physiological significance of ectodomain cleavage
Author(s) -
Smalley D. M.,
Ley K.
Publication year - 2005
Publication title -
journal of cellular and molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.44
H-Index - 130
eISSN - 1582-4934
pISSN - 1582-1838
DOI - 10.1111/j.1582-4934.2005.tb00354.x
Subject(s) - ectodomain , microbiology and biotechnology , l selectin , cleavage (geology) , chemistry , biology , biochemistry , cell adhesion molecule , receptor , paleontology , fracture (geology)
L‐selectin is a cell adhesion molecule consisting of a large, highly glycosylated, extracellular domain, a single spanning transmembrane domain and a small cytoplasmic tail. It is expressed on most leukocytes and is involved in their rolling on inflamed vascular endothelium prior to firm adhesion and transmigration. It is also required for the constitutive trafficking of lymphocytes through secondary lymphoid organs. Like most adhesion molecules, L‐selectin function is regulated by a variety of mechanisms including gene transcription, post‐translational modifications, association with the actin cytoskeleton, and topographic distribution. In addition, it is rapidly downregulated by proteolytic cleavage near the cell surface by ADAM‐17 (TACE) and at least one other “sheddase”. This process of “ectodomain shedding” results in the release of most of the extracellular portion of L‐selectin from the cell surface while retaining the cytoplasmic, transmembrane, and eleven amino acids of the extracellular domain on the cell. This review will examine the mechanism(s) of L‐selectin ectodomain shedding and discuss the physiological implications.