Brunati A M, Contri A, Muenchbach M, James P, Marin O, Pinna L A
Dipartimento di Chimica Biologica, Centro per lo Studio delle Biomembrane del CNR and CRIBI, University of Padova, Viale G. Colombo 3, 35121, Padua, Italy.
FEBS Lett. 2000 Apr 14;471(2-3):151-5. doi: 10.1016/s0014-5793(00)01378-8.
A phosphorylatable protein band of about 94 kDa (as judged by SDS-PAGE) which co-purifies and co-immunoprecipitates with Golgi apparatus casein kinase (G-CK) from rat lactating mammary gland has been shown by mass spectrometric sequence analysis to be identical or very similar to the glucose-regulated protein, GRP94. GRP94 is also readily phosphorylated by G-CK (K(m)=0.2 microM) at seryl sites which are different from the sites affected by casein kinase-2 (CK2) in the same protein. A study with peptide substrates would indicate that the G-CK sites in GRP94 conform to the motif S-R/K-E-X (X being different from D and E) which is not recognized by CK2.
通过SDS-PAGE判断，一条约94 kDa的可磷酸化蛋白条带与大鼠泌乳乳腺中的高尔基体酪蛋白激酶（G-CK）共纯化并共免疫沉淀，质谱序列分析表明其与葡萄糖调节蛋白GRP94相同或非常相似。GRP94也很容易被G-CK（K(m)=0.2 microM）在丝氨酸位点磷酸化，这些位点与同一蛋白中受酪蛋白激酶2（CK2）影响的位点不同。对肽底物的研究表明，GRP94中的G-CK位点符合基序S-R/K-E-X（X不同于D和E），而CK2无法识别该基序。
