Biochemical characterization of the prolyl 3-hydroxylase 1.cartilage-associated protein.cyclophilin B complex.
The rough endoplasmic reticulum-resident protein complex consisting of prolyl 3-hydroxylase 1 (P3H1), cartilage-associated protein (CRTAP), and cyclophilin B (CypB) can be isolated from chick embryos on a gelatin-Sepharose column, indicating some involvement in the biosynthesis of procollagens. Prolyl 3-hydroxylase 1 modifies a single proline residue in the alpha chains of type I, II, and III collagens to (3S)-hydroxyproline. The peptidyl-prolyl cis-trans isomerase activity of cyclophilin B was shown previously to catalyze the rate of triple helix formation. Here we show that cyclophilin B in the complex shows peptidyl-prolyl cis-trans isomerase activity and that the P3H1.CRTAP.CypB complex has another important function: it acts as a chaperone molecule when tested with two classical chaperone assays. The P3H1.CRTAP.CypB complex inhibited the thermal aggregation of citrate synthase and was active in the denatured rhodanese refolding and aggregation assay. The chaperone activity of the complex was higher than that of protein-disulfide isomerase, a well characterized chaperone. The P3H1.CRTAP.CypB complex also delayed the in vitro fibril formation of type I collagen, indicating that this complex is also able to interact with triple helical collagen and acts as a collagen chaperone.
Department of Biochemistry and Molecular Biology, Oregon Health and Science University, and Research Department, Shriners Hospital for Children, Portland, OR 97239, USA.
Yoshihiro
Y
Ishikawa
Jackie
J
Wirz
Janice A
JA
Vranka
Kazuhiro
K
Nagata
Hans Peter
HP
Bächinger
D000818:Animals; D002642:Chick Embryo; D002950:Citrate (si)-Synthase / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D021983:Cyclophilins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016572:Cyclosporine / Q000494:pharmacology; D005109:Extracellular Matrix; D016326:Extracellular Matrix Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006900:Hydroxylation; D018832:Molecular Chaperones; D019696:Peptidylprolyl Isomerase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011393:Procollagen-Proline Dioxygenase / Q000302:isolation & purification / Q000378:metabolism*; D011392:Proline / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017510:Protein Folding; D020349:Surface Plasmon Resonance; D013884:Thiosulfate Sulfurtransferase / Q000737:chemistry / Q000378:metabolism
D024042:Collagen Type I; D024061:Collagen Type III; D016326:Extracellular Matrix Proteins; D018832:Molecular Chaperones; C081786:cyclophilin B; D016572:Cyclosporine; D011392:Proline; D011393:Procollagen-Proline Dioxygenase; C030606:proline, 2-oxoglutarate 3-dioxygenase; D002950:Citrate (si)-Synthase; D013884:Thiosulfate Sulfurtransferase; D021983:Cyclophilins; D019696:Peptidylprolyl Isomerase