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The mouse FKBP23 binds to BiP in ER and the binding of C‐terminal domain is interrelated with Ca 2+ concentration
Author(s) -
Zhang Xiaobin,
Wang Ying,
Li Hui,
Zhang Wanqi,
Wu Di,
Mi Huaifeng
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(04)00024-9
Subject(s) - endoplasmic reticulum , chemistry , binding site , fkbp , n terminus , binding protein , immunoprecipitation , binding domain , biochemistry , microbiology and biotechnology , plasma protein binding , isomerase , recombinant dna , c terminus , sepharose , glutathione , peptide sequence , enzyme , biology , amino acid , gene
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 Ca 2+ 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 Ca 2+ ‐dependent and the switch point is between 2 and 3 mM. By high concentration of Ca 2+ this binding cannot be detected. Furthermore, the Ca 2+ ‐regulated binding of mFKBP23 and mBiP in ER can be detected by means of co‐immunoprecipitation.