TY - JOUR
T1 - Biochemical characterization of the prolyl 3-hydroxylase 1·Cartilage-associated protein·cyclophilin B complex
AU - Ishikawa, Yoshihiro
AU - Wirz, Jackie
AU - Vranka, Janice A.
AU - Nagata, Kazuhiro
AU - Bächinger, Hans Peter
PY - 2009/6/26
Y1 - 2009/6/26
N2 - 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 α chains of type I, II, and III collagens to (3S)-hydroxyproline. The peptidyl-prolyl cistrans 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·RTAP·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.
AB - 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 α chains of type I, II, and III collagens to (3S)-hydroxyproline. The peptidyl-prolyl cistrans 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·RTAP·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.
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U2 - 10.1074/jbc.M109.007070
DO - 10.1074/jbc.M109.007070
M3 - Article
C2 - 19419969
AN - SCOPUS:67650522903
SN - 0021-9258
VL - 284
SP - 17641
EP - 17647
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 26
ER -