Hetmann A, Wujak M, Kowalczyk S
Nicolaus Copernicus University, Faculty of Biology and Environment Protection, Department of Biochemistry, Toruń 87-100, Poland.
Biochemistry (Mosc). 2016 Oct;81(10):1153-1162. doi: 10.1134/S0006297916100126.
The nuclear isoform of nucleoside diphosphate kinase isoenzyme NDPK-I undergoes strong catalytic activation upon its interaction with the active form of phytochrome A (Pfr) in red light. The autophosphorylation or intermolecular transphosphorylation of NDPK-I leads to the formation of phosphoester bonds stable in acidic solution. The phosphate residue of the phosphamide bond in the active center of NDPK-I can also be transferred to serine and threonine residues localized in other proteins, including phytochrome A. Phytochrome A, similarly to NDPK-I, undergoes autophosphorylation on serine and threonine residues and can phosphorylate some potential substrate proteins. The physical interaction between phytochrome A in the Pfr form and NDPK-I results in a significant increase in the kinase activity of NDPK-I. The results presented in this work indicate that NDPK-I may function as a protein kinase regulated by light.
核苷二磷酸激酶同工酶NDPK-I的核异构体在红光下与光敏色素A（Pfr）的活性形式相互作用时会经历强烈的催化激活。NDPK-I的自磷酸化或分子间转磷酸化导致在酸性溶液中稳定的磷酸酯键形成。NDPK-I活性中心中磷酰胺键的磷酸残基也可以转移到其他蛋白质（包括光敏色素A）中定位的丝氨酸和苏氨酸残基上。与NDPK-I类似，光敏色素A在丝氨酸和苏氨酸残基上进行自磷酸化，并可以磷酸化一些潜在的底物蛋白。Pfr形式的光敏色素A与NDPK-I之间的物理相互作用导致NDPK-I的激酶活性显著增加。这项工作中呈现的结果表明，NDPK-I可能作为一种受光调节的蛋白激酶发挥作用。
