title: Cloning from purified high endothelial venule cells of hevin, a close relative of the antiadhesive extracellular matrix protein SPARC.
abstract: High endothelial venules (HEV) in lymphoid tissues support high levels of lymphocyte extravasion from the blood. We purified high endothelial cells from human tonsils by immunomagnetic selection with MECA-79 MAb to construct an HEV cDNA library. Differential screening of this library using cDNA probes from HEV (plus) or flat-walled vessel (minus) endothelial cells allowed us to characterize a novel human cDNA expressed to high levels in HEV. The cDNA encodes a secreted acidic calcium-binding glycoprotein of 664 aa residues, designated hevin, exhibiting 62% identity with the antiadhesive extracellular matrix protein SPARC, over a region of 232 aa spanning more than four fifths of the SPARC coding sequence. The primary structure and sequence of hevin and similar to SPARC-like proteins from rat and quail, called SC1 or QR1. Hevin could contribute to the induction or maintenance of features of the HEV endothelium that facilitate lymphocyte migration.
authors.affiliation: Center for Blood Research, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Girard
authors.forename: T A
authors.initials: TA
authors.lastname: Springer
mesh_terms: D020410:Activated-Leukocyte Cell Adhesion Molecule; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D002448:Cell Adhesion; D003001:Cloning, Molecular; D003370:Coturnix; D018076:DNA, Complementary / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000737:chemistry; D005136:Eye Proteins / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D015723:Gene Library; D005796:Genes; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D006801:Humans; D018189:Immunomagnetic Separation; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D005810:Multigene Family; D009419:Nerve Tissue Proteins / Q000737:chemistry; D015676:Osteonectin / Q000737:chemistry*; D014066:Palatine Tonsil / Q000166:cytology; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014471:Umbilical Veins
chemical_list: D020410:Activated-Leukocyte Cell Adhesion Molecule; D000911:Antibodies, Monoclonal; D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D015676:Osteonectin; C091516:QR1 protein, Coturnix japonica; D012333:RNA, Messenger; C503126:SPARCL1 protein, human; C503128:Sparcl1 protein, rat