Characterization of SMOC-1, a novel modular calcium-binding protein in basement membranes.
We have isolated the novel gene SMOC-1 that encodes a secreted modular protein containing an EF-hand calcium-binding domain homologous to that in BM-40. It further consists of two thyroglobulin-like domains, a follistatin-like domain and a novel domain. Recombinant expression in human cells showed that SMOC-1 is a glycoprotein with a calcium-dependent conformation. Results from Northern blots, reverse transcriptase-PCR, and immunoblots revealed a widespread expression in many tissues. Immunofluorescence studies with an antiserum directed against recombinant human SMOC-1 demonstrated a basement membrane localization of the protein and additionally its presence in other extracellular matrices. Immunogold electron microscopy confirmed the localization of SMOC-1 within basement membranes in kidney and skeletal muscle as well as its expression in the zona pellucida surrounding the oocyte.
Institute for Biochemistry, Medical Faculty, University of Cologne, Joseph-Stelzmann Strasse 52, D-50931 Cologne, Germany.
Christian
C
Vannahme
Neil
N
Smyth
Nicolai
N
Miosge
Silke
S
Gösling
Christian
C
Frie
Mats
M
Paulsson
Patrik
P
Maurer
Ursula
U
Hartmann
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001485:Basement Membrane / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002942:Circular Dichroism; D020832:EF Hand Motifs; D005260:Female; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000648:ultrastructure; D007797:Laminin / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism / Q000648:ultrastructure; D015676:Osteonectin; D010053:Ovary / Q000378:metabolism / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution; D015044:Zona Pellucida / Q000737:chemistry / Q000378:metabolism
D002135:Calcium-Binding Proteins; D006023:Glycoproteins; D007797:Laminin; D015676:Osteonectin; D011994:Recombinant Proteins; C468135:SMOC1 protein, human