Molecular cloning of SC1: a putative brain extracellular matrix glycoprotein showing partial similarity to osteonectin/BM40/SPARC.
We describe the cloning of SC1, a novel cDNA that was selected from a rat brain expression library using a mixed polyclonal antibody directed against synaptic junction glycoproteins. SC1 detects a 3.2 kb mRNA expressed throughout postnatal development of the brain and present at high levels in the adult. In situ hybridization reveals that the SC1 mRNA is expressed widely in the brain and is present in many types of neurons. DNA sequence data suggest that the SC1 product is a secreted, calcium binding glycoprotein. Strikingly, the carboxy-terminal region of the SC1 protein shows substantial similarity to the extracellular matrix glycoprotein osteonectin/BM40/SPARC. These data are consistent with the hypothesis that SC1 is an extracellular matrix glycoprotein in the brain.
Department of Zoology, University of Toronto, Ontario, Canada.
I G
IG
Johnston
T
T
Paladino
J W
JW
Gurd
I R
IR
Brown
D020410:Activated-Leukocyte Cell Adhesion Molecule; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D001923:Brain Chemistry; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D015676:Osteonectin / Q000235:genetics* / Q000276:immunology; D011506:Proteins / Q000276:immunology / Q000378:metabolism; D012313:RNA / Q000235:genetics; D051381:Rats
D020410:Activated-Leukocyte Cell Adhesion Molecule; D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D015676:Osteonectin; D011506:Proteins; D012313:RNA; D004247:DNA