Isolation and characterization of Dictyostelium thymidine kinase 1 as a calmodulin-binding protein

Effects of Intracellular Calcium Chelation and Pifithrin-α on Deoxynucleotide Metabolism in Human Lymphocytes

“…Radioactivity was measured in ethanol-soluble (nucleotide) and ethanol-insoluble (DNA) fractions as desribed in Csapó et al [2] that BAPTA-AM but not pifithrin-alpha partially rescues the spontaneous inactivation of TK1, raising the possibility that reduced cytosolic calcium levels might stabilize the enzyme. This observation is in sharp contrast with the suggestion of O'Day and coworkers [6] who assumed that human TK1-based on sequence analogy-might be a Ca/calmodulin-activated enzyme.…”

Dictyostelium discoideum Salvages Purine Deoxyribonucleosides by Highly Specific Bacterial-like Deoxyribonucleoside Kinases

“…25 The thyB gene is located on chromosome 5 and the 684-base-pair open reading frame (ORF) consists of three exons. The ORF is predicted to encode a 227-amino-acid protein with high homology to the human TK1, confirming the report by O'day et al 19 The corresponding protein was named DdTK1. The DdTK1 has 45% overall amino acid identity to human TK1.…”

“…[15][16][17][18] During the progress of the work presented herein O'day et al described a calmodulin binding TK1 in D. discoideum; however, the enzyme remained uncharacterized with respect to its K m and V max . 19 The non-TK1-like family, on the other hand, is composed of a group of eukaryotic dNKs and a distinct group of bacterial dNKs. The bacterial non-TK1-like kinases were so far only described in Gram-positive bacteria, and their biochemical properties and substrate specificities vary dramatically.…”