Figure 1.

Summary of nuclear functions of NME proteins. In response to environmental stimuli, such as DNA damage, NME proteins translocate into the nucleus via an as yet unknown mechanism. Nuclear NME proteins may execute a variety of functions, including (a) direct binding and cleavage of DNA in promoter regions of genes with specific secondary structure, such as nuclease-hypersensitive elements (NHE), to either promote or inhibit transcription; (b) binding to transcription factors to indirectly influence gene expression; and (c) recruitment to double-stranded breaks, either contributing to end resection via 3′–5′ exonuclease activity (3′–5′ EXO), or contributing via nucleoside diphosphate kinase (NDPK) activity to the local pool of nucleoside triphosphates (NTPs) required for polymerase-mediated ′fill-in′ steps of double-stranded break repair