Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow.
In inflamed venules, leukocytes use P-selectin glycoprotein ligand-1 (PSGL-1) to roll on P-selectin and E-selectin and to activate integrin alphaLbeta2 (lymphocyte function-associated antigen-1, LFA-1) to slow rolling on intercellular adhesion molecule-1 (ICAM-1). Studies in cell lines have suggested that PSGL-1 requires its cytoplasmic domain to localize in membrane domains, to support rolling on P-selectin, and to signal through spleen tyrosine kinase (Syk). We generated "DeltaCD" mice that express PSGL-1 without the cytoplasmic domain. Unexpectedly, neutrophils from these mice localized PSGL-1 normally in microvilli, uropods, and lipid rafts. DeltaCD neutrophils expressed less PSGL-1 on their surfaces because of inefficient export from the endoplasmic reticulum. Limited digestion of wild-type neutrophils with O-sialoglycoprotein endopeptidase was used to reduce the PSGL-1 density to that on DeltaCD neutrophils. At matched PSGL-1 densities, both DeltaCD and wild-type neutrophils rolled similarly on P-selectin. However, DeltaCD neutrophils rolling on P-selectin did not trigger Syk-dependent activation of LFA-1 to slow rolling on ICAM-1. These data demonstrate that the PSGL-1 cytoplasmic domain is dispensable for leukocyte rolling on P-selectin but is essential to activate beta2 integrins to slow rolling on ICAM-1.
Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
Jonathan J
JJ
Miner
Lijun
L
Xia
Tadayuki
T
Yago
János
J
Kappelmayer
Zhenghui
Z
Liu
Arkadiusz G
AG
Klopocki
Bojing
B
Shao
J Michael
JM
McDaniel
Hendra
H
Setiadi
David W
DW
Schmidtke
Rodger P
RP
McEver
D000595:Amino Acid Sequence; D000818:Animals; D018821:CD18 Antigens / Q000502:physiology; D018056:Hemorheology; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1 / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology; D036904:Leukocyte Rolling / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D021962:Membrane Microdomains / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008871:Microvilli / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019007:P-Selectin / Q000502:physiology; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D000072377:Syk Kinase
D018821:CD18 Antigens; C090509:Icam1 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D019007:P-Selectin; C084882:P-selectin ligand protein; D010446:Peptide Fragments; D011994:Recombinant Proteins; D018799:Intercellular Adhesion Molecule-1; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; C000606897:Syk protein, mouse