title: Characterization of cyclophilin 40: highly conserved protein that directly associates with Hsp90.
abstract: Cyclophilin 40 (CyP4O) is a recently identified member of the cyclophilin family that may be a component of unactivated steroid receptor complexes. It consists of an N-half portion that is highly homologous to cyclophilin A and has peptidyl prolyl isomerase (PPIase) activity, and a C-half portion that resembles the C-terminal portion of FKBP52 (FK506 binding protein 52), another component of unactivated steroid receptor complexes. To better understand the structure and functional characteristics of this new class of cyclophilin, we have raised monoclonal antibodies against the C-half portion of human CyP4O. Immunostaining with the antibodies showed its preferential localization in cytoplasm. One antibody cross-reacted with a 45 kDa protein in yeast, suggesting high conservation throughout evolution. A CyP4O-associated protein was isolated from rabbit reticulocyte lysate by means of an affinity resin, and was identified as hsp90. The C-half portion of CyP4O was necessary and sufficient for the interaction.
authors.affiliation: Tokyo Research Laboratories, Kyowa Hakko Kogyo, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yokoi
authors.forename: H
authors.initials: H
authors.lastname: Kondo
authors.forename: A
authors.initials: A
authors.lastname: Furuya
authors.forename: N
authors.initials: N
authors.lastname: Hanai
authors.forename: J E
authors.initials: JE
authors.lastname: Ikeda
authors.forename: H
authors.initials: H
authors.lastname: Anazawa
mesh_terms: D000591:Amino Acid Isomerases / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002352:Carrier Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D017124:Conserved Sequence; D000081406:Peptidyl-Prolyl Isomerase F; D021983:Cyclophilins; D003593:Cytoplasm / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D019143:Evolution, Molecular; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008856:Microscopy, Fluorescence; D019696:Peptidylprolyl Isomerase; D011485:Protein Binding; D011817:Rabbits; D011987:Receptors, Steroid; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012156:Reticulocytes / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism; D013552:Swine; D022021:Tacrolimus Binding Proteins
chemical_list: D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D000081406:Peptidyl-Prolyl Isomerase F; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D011987:Receptors, Steroid; D011993:Recombinant Fusion Proteins; D000591:Amino Acid Isomerases; D021983:Cyclophilins; D022021:Tacrolimus Binding Proteins; D019696:Peptidylprolyl Isomerase