Identification of simian cyclophilin A as a calreticulin-binding protein in yeast two-hybrid screen and demonstration of cyclophilin A interaction with calreticulin.
Cyclophilin A (CyPA) was identified as one of the calreticulin (CR)-binding proteins in a yeast two-hybrid screen utilizing simian cDNA expression-library. The simian CyPA protein had 96% identity with that of human, differing only at eight amino acid residues. We further established CyPA-CR interaction by incubation of glutathione transferase-fused CyPA (GST-CyPA) and CR proteins with CV-1 cyto-lysates, followed by CR and CyPA-specific immuno-blot analysis. The immunosuppressive drug cyclosporin A, a CyPA ligand, did not inhibit CyPA-CR interaction. Our results established a new property of CyPA binding activity to CR. Since CR is a Ca2+-binding protein, CR-CyPA interactions may be important in signaling pathways for induction of Ca2+-dependent cellular processes.
Reddy
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PA
Section of Viral Pathogenesis and Adverse Reactions, Laboratory of Pediatric and Respiratory Viral Diseases, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
Atreya
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D037282:Calreticulin; D016572:Cyclosporine / Q000494:pharmacology; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D000882:Haplorhini; D006801:Humans; D006822:Hybrid Cells; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015003:Yeasts / Q000235:genetics
D002135:Calcium-Binding Proteins; D037282:Calreticulin; D007166:Immunosuppressive Agents; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; D016572:Cyclosporine; D005982:Glutathione Transferase; D019696:Peptidylprolyl Isomerase