Molecular characterization of a new immunoglobulin superfamily protein with potential roles in opioid binding and cell contact.
A purified opioid-binding protein has been characterized by cDNA cloning. The cDNA sequence predicts an extracellularly located glycoprotein of 345 amino acids. This protein does not possess a membrane-spanning domain but contains a C-terminal hydrophobic sequence characteristic of membrane attachment by a phosphatidylinositol linkage. It displays homology to the immunoglobulin protein superfamily, featuring three domains that resemble disulfide-bonded constant regions. More specifically, the protein is most homologous to a subfamily of proteins which includes the neural cell adhesion molecule (NCAM) and myelin-associated glycoprotein (MAG) and one subgroup of the tyrosine kinase growth factor receptors comprising the platelet-derived growth factor receptor (PDGF R), the colony-stimulating factor 1 receptor (CSF-1 R) and the c-kit protooncogene. These sequence homologies suggest that the protein could be involved in either cell recognition and adhesion, peptidergic ligand binding or both.
Schofield
P R
PR
Genentech, Inc., Department of Developmental Biology, South San Francisco, CA 94080.
McFarland
K C
KC
Hayflick
J S
JS
Wilcox
J N
JN
Cho
T M
TM
Roy
S
S
Lee
N M
NM
Loh
H H
HH
Seeburg
P H
PH
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000235:genetics; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000502:physiology; D002417:Cattle; D015815:Cell Adhesion Molecules; D004247:DNA / Q000235:genetics; D005803:Genes, Immunoglobulin; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D015394:Molecular Structure; D005810:Multigene Family
D000954:Antigens, Surface; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D008562:Membrane Glycoproteins; D004247:DNA