Nonradioactive Assay to Measure Polynucleotide Phosphorylation of Small Nucleotide Substrates.

Autor: Pillon MC; Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Department of Health and Human Services, National Institutes of Health., Stanley RE; Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Department of Health and Human Services, National Institutes of Health; robin.stanley@nih.gov.
Jazyk: angličtina
Zdroj: Journal of visualized experiments : JoVE [J Vis Exp] 2020 May 08 (159). Date of Electronic Publication: 2020 May 08.
DOI: 10.3791/61258
Abstrakt: Polynucleotide kinases (PNKs) are enzymes that catalyze the phosphorylation of the 5' hydroxyl end of DNA and RNA oligonucleotides. The activity of PNKs can be quantified using direct or indirect approaches. Presented here is a direct, in vitro approach to measure PNK activity that relies on a fluorescently-labeled oligonucleotide substrate and polyacrylamide gel electrophoresis. This approach provides resolution of the phosphorylated products while avoiding the use of radiolabeled substrates. The protocol details how to set up the phosphorylation reaction, prepare and run large polyacrylamide gels, and quantify the reaction products. The most technically challenging part of this assay is pouring and running the large polyacrylamide gels; thus, important details to overcome common difficulties are provided. This protocol was optimized for Grc3, a PNK that assembles into an obligate pre-ribosomal RNA processing complex with its binding partner, the Las1 nuclease. However, this protocol can be adapted to measure the activity of other PNK enzymes. Moreover, this assay can also be modified to determine the effects of different components of the reaction, such as the nucleoside triphosphate, metal ions, and oligonucleotides.
Databáze: MEDLINE