Cloning and characterization of cyclophilin C-associated protein: a candidate natural cellular ligand for cyclophilin C.
We report the protein purification and the cloning and characterization of a cDNA encoding the proteins that bind with high affinity to cyclophilin C (Cyp-C) in the absence of cyclosporin A. Transfection of this cDNA into COS cells directs the production of a glycoprotein of 77 kDa that binds to Cyp-C in the absence, but not the presence, of cyclosporin A. Homology comparisons reveal that this protein and gene, termed CyCAP for Cyp-C-associated protein, possess a cysteine-rich domain (scavenger receptor cysteine-rich domain) found in a variety of cell-surface molecules; the rest of the sequence is apparently specific. This result raises the possibility that Cyp-C serves as a mediator or regulator of an as-yet-unidentified signal or cellular process initiated via the Cyp-C-associated protein.
Friedman
J
J
Department of Pathology, Stanford University School of Medicine, CA 94305.
Trahey
M
M
Weissman
I
I
D000591:Amino Acid Isomerases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001854:Bone Marrow Cells; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D000072622:Cyclophilin C; D021983:Cyclophilins; D003524:Cyclosporins / Q000378:metabolism*; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D002352:Carrier Proteins; D003524:Cyclosporins; D006023:Glycoproteins; D010446:Peptide Fragments; C082349:Ppicap protein, mouse; D011994:Recombinant Proteins; D000591:Amino Acid Isomerases; D021983:Cyclophilins; D000072622:Cyclophilin C