Phosphorylation of surface E-selectin and the effect of soluble ligand (sialyl Lewisx) on the half-life of E-selectin.
E-selectin (ELAM-1) is an adhesion molecule for leukocytes that is transiently expressed on endothelial cells. Following cell surface expression of E-selectin on human umbilical vein endothelial cells (HUVEC) stimulated with tumor necrosis factor, the induced E-selectin molecules are rapidly degraded. The kinetics of turnover of surface disposed E-selectin were investigated. The rapid disappearance of surface E-selectin is temperature dependent and sensitive to the lysosomotropic agent chloroquine. The half-life of E-selectin is not affected by inclusion of soluble sialyl Lewis x (sLex) ligands in the medium. Surface E-selectin is phosphorylated on one or more serine residues, but this modification is not obviously related to internalization.
Smeets
E F
EF
Department of Surgery, State University of Limburg, Maastricht, The Netherlands.
de Vries
T
T
Leeuwenberg
J F
JF
van den Eijnden
D H
DH
Buurman
W A
WA
Neefjes
J J
JJ
D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D002738:Chloroquine / Q000494:pharmacology; D019040:E-Selectin; D006207:Half-Life; D006801:Humans; D016256:Lewis X Antigen / Q000502:physiology*; D010766:Phosphorylation; D012694:Serine / Q000378:metabolism; D013696:Temperature
D015815:Cell Adhesion Molecules; D019040:E-Selectin; D016256:Lewis X Antigen; D012694:Serine; D002738:Chloroquine