title: Expression pattern of alternatively spliced PECAM-1 isoforms in hematopoietic cells and platelets.
abstract: PECAM-1 (CD31) is a cell adhesion molecule that is highly expressed in the endothelium. Hematopoietic cells including platelets, monocytes, neutrophils, and some T cells also express moderate levels of PECAM-1. PECAM-1 undergoes alternative splicing generating a number of isoforms in the endothelium. However, the expression of PECAM-1 isoforms in hematopoietic cells and platelets has not been determined. Here, we examined the expression pattern of PECAM-1 isoforms in human and rodent hematopoietic cells and platelets by RT-PCR and DNA sequencing analysis. Our results showed that multiple PECAM-1 isoforms are expressed in a cell-type and species-specific pattern. We identified seven human PECAM-1 isoforms, six murine PECAM-1 isoforms, and four rat PECAM-1 isoforms. The full-length PECAM-1 was the predominant isoform detected in human cells. The PECAM-1 isoforms that lack exon 14 and 15 (delta14&15) or delta12,14&15 were the predominant isoform in rodent cells. In addition, we identified a novel PECAM-1 isoform, delta13&14, in human hematopoietic cells. Thus, hematopoietic cells express multiple isoforms of PECAM-1 in a pattern similar to that observed in the endothelium of the same species. The regulated expression of these isoforms may be important during hematopoiesis and transendothelial migration.
authors.affiliation: Department of Ophthalmology and Visual Sciences Madison, University of Wisconsin Medical School, Madison, Wisconsin 53792-4673, USA.
authors.forename: Yongji
authors.initials: Y
authors.lastname: Wang
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001792:Blood Platelets / Q000378:metabolism*; D015152:Blotting, Northern; D002460:Cell Line; D002465:Cell Movement; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D005091:Exons; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis* / Q000097:blood / Q000737:chemistry*; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014407:Tumor Cells, Cultured; D020298:U937 Cells
chemical_list: D018076:DNA, Complementary; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D020033:Protein Isoforms; D012333:RNA, Messenger