The binding of FKBP23 to BiP modulates BiP's ATPase activity with its PPIase activity.
Peptidyl-prolyl cis-trans-isomerases (PPIases) are enzymes that can cis-trans-isomerize a Xaa-Pro peptide bond. Three families of PPIases are known: cyclophilins, FKBPs, and parvulins. The physiological functions of the PPIases are only poorly understood. In previous work, we reported that the mouse FK506-binding protein 23 (mFKBP23), which comprises an N-terminal PPIase domain and a C-terminal domain with Ca(2+)-binding sites, binds to mBiP in the endoplasmic reticulum (ER) and this binding is affected by the Ca(2+) concentration. In this study, we demonstrate the ability of mFKBP23 to modulate the ATPase activity of BiP, and that the bound mFKBP23, but not the free mFKBP23, can suppress the ATPase activity of mBiP through its PPIase activity.
Wang
Ying
Y
Biochemical Section of Key Laboratory of Functional Polymer Materials, The Ministry of Education of China, Institute of Polymer Chemistry, Chemical School of Nankai University, 300071 Tianjin, PR China.
Han
Ruifang
R
Wu
Di
D
Li
Jie
J
Chen
Chen
C
Ma
Hui
H
Mi
Huaifeng
H
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D003067:Coenzymes / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D000091342:Endoplasmic Reticulum Chaperone BiP; D004789:Enzyme Activation; D006360:Heat-Shock Proteins / Q000378:metabolism*; D022781:Hepatocytes / Q000378:metabolism*; D051379:Mice; D018832:Molecular Chaperones / Q000378:metabolism*; D019696:Peptidylprolyl Isomerase / Q000378:metabolism*; D011485:Protein Binding; D022021:Tacrolimus Binding Proteins / Q000378:metabolism*
D003067:Coenzymes; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; C074856:FKBP3 protein, human; D000251:Adenosine Triphosphatases; D022021:Tacrolimus Binding Proteins; D019696:Peptidylprolyl Isomerase