Interaction between CREG1 and HSPD1 in vitro and in vivo. (A and B) 293 T cells were transfected with Creg1-HA plasmid and Hspd1-FLAG plasmid together. Co-IP of CREG1 and HSPD1 in 293 T cells. (C) Confocal microscopy analysis of the colocalization of CREG1-GFP and HSPD1, scale bars: 20 μm. (D and E) Co-IP assay showed the interaction between CREG1 and HSPD1 in the skeletal muscle protein from 9-month-old creg1;Ckm-Cre and Creg1fl/fl mice. (F and G) Western blotting and quantification analysis showed the expression of HSPD1 protein in the skeletal muscles of 3-month or 9-month-old mice Creg1fl/fl and creg1;Ckm-Cre mice. (H and I) Western blotting analysis demonstrated the expression of HSPD1 protein in the skeletal muscles of 9-month-old creg1;Ckm-Cre with or without reCREG1 protein treatment. (J and K) Western blotting and quantification analysis showed the expression of HSPD1 protein in siScramble, siCreg1, and siCreg1+ MG132 (10 μmol/L) cells. (L and M) Western blotting and quantification analysis showed the expression of CREG1 protein in siScramble, siHspd1, and siHspd1+ MG132 (10 μmol/L) cells. Data are shown as mean ± SEM, **p < 0.01, &p < 0.01