The mouse FKBP23 binds to BiP in ER and the binding of C‐terminal domain is interrelated with Ca2+ concentration

FEBS Letters

Zhang, Xiaobin¹  Wang, Ying¹  Li, Hui¹  Mi, Huaifeng¹  Zhang, Wanqi¹  Wu, Di¹ 

[1]Biochemical Section of State Key Laboratory of Functional Polymer Materials for Adsorption and Separation, Chemical School of Nankai University, 300071 Tianjin, PR China

关键词: Peptidyl-prolyl isomerase;    FK506 binding protein 23;    Immunoglobulin binding protein;    Ca2+-dependent protein interaction;    mFKBP;    mouse FK506 binding protein;    mBiP;    mouse immunoglobulin binding protein;    ER;    endoplasmic reticulum;    PPIase;    peptidyl-prolyl cis-trans isomerase;    GST;    glutathione S-transferase;    IP;    immunoprecipitation;   

DOI  :  10.1016/S0014-5793(04)00024-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

FK506 binding protein 23 from mouse (mFKBP23) is a peptidyl-prolyl cis-trans isomerase (PPIase) from the endoplasmic reticulum (ER), which consists of an N-terminal PPIase domain and a C-terminal domain with Ca²⁺ binding sites. The assay of adsorption from ER extract with glutathione S-transferase-mFKBP23 attached to glutathione-Sepharose 4B shows that mFKBP23 binds to mouse immunoglobulin binding protein (mBiP). The same assay with the recombinant proteins of the N- and C-termini of mFKBP23 shows that the binding of the C-terminus is Ca²⁺-dependent and the switch point is between 2 and 3 mM. By high concentration of Ca²⁺ this binding cannot be detected. Furthermore, the Ca²⁺-regulated binding of mFKBP23 and mBiP in ER can be detected by means of co-immunoprecipitation.

【 授权许可】

Unknown