P-selectin glycoprotein ligand 1; PSGL-1; selectin P ligand; CD162 (SELPLG)

^[1]^[2]^[3]

Function

SLe(x)-type glycan
high affinity Ca+2-dependent interactions with selectins
- E-selection
- P-selectin
- L-selectin
via 2, mediates rapid rolling of leukocytes over vascular surfaces during the initial steps in inflammation
PSGL1 is critical for the initial leukocyte capture
interacts with SNX20

homodimer; disulfide-linked
complex, core-2, sialylated & fucosylated O-linked oligosaccharides, at least some of which appear to contain poly-N-acetyllactosamine with varying degrees of substitution
disialylated or neutral forms of core-2 tetrasaccharide: galbeta1-->4GlcNAcbeta1-->6(galbeta1-->3)galNAcOH
GlcN:galN ratio is approximately 2:1
man:fuc ratio 3:5.
contains about 14% fucose with alpha-1,3 linkage present in two forms:
- disialylated, monofucosylated glycan
- monosialylated, trifucosylated glycan with polylactosamine backbone
fucosylated forms carry the Lewis antigen & are important for interaction with selectins & for functioning in leukocyte rolling
modification containing sialyl Lewis X glycan is on Thr-57
no sulfated O-glycans
interaction with P-selectin, E-selectin & L-selectins, through their lectin/EGF domains, is required for promoting recruitment & rolling of leukocytes
these interactions require sialyl Lewis X glycan modification but there is a differing dependence for Tyr sulfations
high affinity P-selectin binding has a preferred requirement for the isomer sulfated on both Tyr-48 & Tyr-51 (dimerization appears not to be required)
L-selectin binding requires predominantly sulfation on Tyr-51 with sulfation on Tyr-48 playing only a minor role
E-selectin/SELE binds with much lower affinity & requires SLe(x) epitope, but apparantly not Tyr sulfation