Molecular cloning and characterization of bovine P-selectin glycoprotein ligand-1.
Human P-selectin glycoprotein ligand-1 (PSGL-1) is a dimeric membrane mucin expressed on leukocytes that binds selectins. Here, we report that the open reading frame (ORF) of bovine PSGL-1 (bPSGL-1) cDNA is 1284 base pairs in length, predicting a protein of 427 amino acids including an 18-amino-acid signal peptide, an extracellular region with a mucin-like domain, and transmembrane and cytoplasmic domains. The amino acid sequence of bPSGL-1 demonstrated 52, 49 and 40% overall homology to equine, human and mouse, respectively. A single extracellular cysteine, at the transmembrane and extracellular domain junction, suggests a disulfide-bonding pattern. Alignment of bovine with equine, human and mouse PSGL-1 demonstrates high conservation of transmembrane and cytoplasmic domains, but diversity of the extracellular domain, especially in the anionic NH(2)-terminal of PSGL-1, the putative P-selectin binding domain. In the NH(2)-terminal of bPSGL-1, there are three potential tyrosine sulfation sites and three potential threonine O-glycosylation sites, all of which are required for P-selectin binding in human PSGL-1 (hPSGL-1). bPSGL-1 shares only 57% homology in amino acid sequence with the corresponding epitope region which binds the monoclonal antibody PL1 for hPSGL-1, and no cross-reactivity was found in bovine leukocytes. In summary, bPSGL-1 shares homology with hPSGl-1, but has differences in the putative extracellular P-selectin binding domain.
Xu
Jin
J
Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706-1102, USA.
Cai
Jun
J
Barger
Brittany A
BA
Peek
Simon
S
Darien
Benjamin J
BJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle / Q000235:genetics / Q000276:immunology*; D000939:Epitopes / Q000032:analysis; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012313:RNA / Q000737:chemistry / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D000939:Epitopes; D008562:Membrane Glycoproteins; C084882:P-selectin ligand protein; D012313:RNA