Expression of glycoprotein VI in vascular endothelial cells.
Glycoprotein (GP) VI, a collagen receptor, plays a important role in collagen-mediated platelet aggregation and adhesion. To date, GPVI expression has been found only in platelets and megakaryocytes. In the present studies, we have demonstrated that GPVI was also expressed in cultured human umbilical vein endothelial cells (HUVEC) at both transcript and protein levels. Using a GPVI-specific probe, a approximately 6-kb band was detected in HUVEC as well as in platelets and megakaryoblastic cell lines by Northern blotting. Using polyclonal antibodies raised against platelet GPVI peptides, the same size band (57 kDa) was labeled with convulxin (CVX) after immuo-precipitation in both HUVEC and platelet lysates. In addition, a approximately 70-kDa band was also labeled in HUVEC. Surface expression of GPVI in HUVEC was confirmed by flow cytometry with GPVI-specific IgG or by direct labeling with FITC-conjugated CVX. Since HUVEC lack FcRgamma chain that forms complex with GPVI in platelets for signaling process, the function of GPVI in vascular endothelial cells remains to be determined.
Sun
Bing
B
Maryland Research Laboratories, Otsuka Maryland Research Institute, Inc. 9900 Medical Center Drive, Rockville, MD 20850, USA. bings@otsuka.com
Tao
Lian
L
Lin
Shihua
S
Calingasan
Noel Y
NY
Li
Jess
J
Tandon
Narendra N
NN
Yoshitake
Masuhiro
M
Kambayashi
Jun-ichi
J
D015152:Blotting, Northern; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000737:chemistry / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000737:chemistry* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D010980:Platelet Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000032:analysis; D017452:Receptors, IgG / Q000032:analysis; D014471:Umbilical Veins / Q000166:cytology
D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D017452:Receptors, IgG; C098341:platelet membrane glycoprotein VI