Diverse roles of nucleoside diphosphate kinase in genome stability and growth fitness.

Nucleoside diphosphate kinase (NDK), a ubiquitous enzyme, catalyses reversible transfer of the γ phosphate from nucleoside triphosphates to nucleoside diphosphates and functions to maintain the pools of ribonucleotides and deoxyribonucleotides in the cell. As even a minor imbalance in the nucleotide pools can be mutagenic, NDK plays an antimutator role in maintaining genome integrity. However, the mechanism of the antimutator roles of NDK is not completely understood. In addition, NDKs play important roles in the host-pathogen interactions, metastasis, gene regulation, and various cellular metabolic processes. To add to these diverse roles of NDK in cells, a recent study now reveals that NDK may even confer mutator phenotypes to the cell by acting on the damaged deoxyribonucleoside diphosphates that may be formed during the oxidative stress. In this review, we discuss the roles of NDK in homeostasis of the nucleotide pools and genome integrity, and its possible implications in conferring growth/survival fitness to the organisms in the changing environmental niches.