Stabilin-1 and -2 constitute a novel family of fasciclin-like hyaluronan receptor homologues.
MS-1, a high-molecular-mass protein expressed by non-continuous and angiogenic endothelial cells and by alternatively activated macrophages (Mphi2), and the hepatic sinusoidal endothelial hyaluronan clearance receptor are similar with respect to tissue distribution and biochemical characteristics. In the present study we purified these proteins by immuno- and hyaluronan-affinity chromatography respectively, sequenced tryptic peptides and generated full-length cDNA sequences in both mouse and human. The novel genes, i.e. stabilin-1 and stabilin-2, code for homologous transmembrane proteins featuring seven fasciclin-like adhesion domains, 18-20 epidermal-growth-factor domains, one X-link domain and three to six B-(X(7))-B hyaluronan-binding motifs. Northern-blotting experiments revealed the presence of both stabilins in organs with predominant endothelial sinuses such as liver, spleen and lymph node: stabilin-1 mRNA was also detected in organs with predominant Mphi2 cells, such as placenta, and in interleukin-4/glucocorticoid-stimulated Mphi2 cells in vitro. A polyclonal antibody made against human recombinant stabilin-1 confirmed the expression of stabilin-1 protein in splenic sinus endothelial cells in vivo and in Mphi2 in vitro. On the basis of high similarity at the protein level and the unique domain composition, which differs from that of all other known fasciclin-like proteins and hyaluronan receptors, stabilin-1 and stabilin-2 define a novel family of fasciclin-like hyaluronan receptor homologues that might play a role in cell-cell and cell-matrix interactions in vascular function and inflammatory processes.
Politz
Oliver
O
Department of Dermatology, University Medical Center Mannheim, Ruprecht Karls University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68135 Mannheim, Germany.
Gratchev
Alexei
A
McCourt
Peter A G
PA
Schledzewski
Kai
K
Guillot
Pierre
P
Johansson
Sophie
S
Svineng
Gunbjorg
G
Franke
Peter
P
Kannicht
Christoph
C
Kzhyshkowska
Julia
J
Longati
Paola
P
Velten
Florian W
FW
Johansson
Staffan
S
Goerdt
Sergij
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015816:Cell Adhesion Molecules, Neuronal / Q000737:chemistry* / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D018960:Hyaluronan Receptors / Q000737:chemistry* / Q000235:genetics; D008264:Macrophages / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D016201:Receptors, Lymphocyte Homing; D017386:Sequence Homology, Amino Acid
D015816:Cell Adhesion Molecules, Neuronal; D017931:DNA Primers; D018960:Hyaluronan Receptors; D016201:Receptors, Lymphocyte Homing; C449926:STAB1 protein, human; C449927:STAB2 protein, human; C486732:Stab1 protein, mouse; C486733:Stab2 protein, mouse