2.7.1.78	malfunction	depletion of Nol9 leads to a severe impairment of ribosome biogenesis. Upon Nol9 knockdown, specific maturation defect at the 5' end of the predominant 5.8S short-form rRNA (5.8SS) occur, possibly due to the Nol9 requirement for 5'>3' exonucleolytic trimming	722115	
2.7.1.78	malfunction	knockdown of polynucleotide kinase and aprataxin-like forkhead-associated using siRNA reduces rejoining of two incompatible I-SceI-generated DNA ends by 50%	722727	
2.7.1.78	malfunction	mutations lead to a loss of enzyme interaction with the tRNA splicing endonuclease complex, largely reduced pretRNA cleavage activity, and accumulation of linear tRNA introns. The affected individuals develop severe motor-sensory defects, cortical dysgenesis, and microcephaly	729562	
2.7.1.78	malfunction	Pnk1 deletion in fission yeast renders cells sensitive to camptothecin	716975	
2.7.1.78	malfunction	PNKP depletion in human cells renders cells sensitive to camptothecin. A small molecule inhibitor of PNKP phosphatase activity enhances the sensitivity of cells to IR and camptothecin. Enzyme mutational defects can cause neurological disorders with various symptoms, e.g. a severe neurological autosomal recessive disease characterized by microcephaly, intractable seizures and developmental delay	716975	
2.7.1.78	malfunction	polynucleotide kinase Grc3 depletion results in rRNA processing defects	739186	
2.7.1.78	malfunction	the lack of CLP1 kinase activity leads to progressive motor neuron loss and accumulation of novel 5' leader-5' exon tRNA fragments	729174	
2.7.1.78	metabolism	polynucleotide 5-kinase Nol9 is involved in ribosomal RNA processing	722115	
2.7.1.78	metabolism	the enzyme is part of the Pnkp-Hen1 RNA repair pathway, overview	723764	
2.7.1.78	metabolism	the enzyme is required for 60S ribosomal particles synthesis	739186	
2.7.1.78	additional information	molecular architecture of the enzyme, overview. The mammalian enzyme preferentially phosphorylates 5'-hydroxyl termini within nicked, gapped or double-strand breaks with single-stranded 3'-overhanging ends, whereas single-stranded 5'-termini or blunt double-stranded ends are phosphorylated less efficiently. The selective recognition of the larger, double-stranded DNA substrates is effected by a broad DNA recognition groove composed of two distinct positively charged surfaces. Mechanisms of single-strand break and double-strand break repairs, and of base excision repair, overview	716975	
2.7.1.78	additional information	molecular architecture of the enzyme, overview. The mammalian enzyme preferentially phosphorylates 5'-hydroxyl termini within nicked, gapped or DSBs with single-stranded 3' overhanging ends, whereas single-stranded 5'-termini or blunt double-stranded ends are phosphorylated less efficiently. The selective recognition of the larger, double-stranded DNA substrates is effected by a broad DNA recognition groove composed of two distinct positively charged surfaces. Mechanisms of single-strand break and double-strand break repairs, and base excision repair, overview	716975	
2.7.1.78	additional information	molecular architecture of the enzyme, overview. The phage PNK DNA binding cleft forms a narrow channel leading to the conserved catalytic aspartic acid residue that accommodates single-stranded, but not double-stranded, substrates. Mechanisms of single-strand break and double-strand break repairs, overview	716975	
2.7.1.78	additional information	PNK domain architecture, overview	723644	
2.7.1.78	additional information	structure and mechanism of the polynucleotide kinase component of the bacterial Pnkp-Hen1 RNA repair system, the enzyme has an autonomous kinase domain, overview. Pnkp-Hen1 RNA repair pathway confers protective immunity to recurrent RNA damage	723764	
2.7.1.78	additional information	the nuclease activity of polynucleotide kinase and aprataxin-like forkhead-associated is not affected by Ku or XRCC4-DNA ligase IV	722727	
2.7.1.78	physiological function	bifunctional polynucleotide kinase/phosphatase contains both DNA 5'-kinase and 3'-phosphatase activities required for restoration of 3'-hydroxyls and 5'-phosphates needed to seal the broken DNA. Cellular DNA is constantly assaulted by ionizing radiation and reactive oxygen species. This damage, along with the products of some DNA repair enzymes, may contain 5' hydroxyls or 3' phosphates. These are converted by PNK to 5' phosphates and 3' hydroxyls, which are required for DNA polymerases and DNA ligases to complete repair of the damaged DNA. Productive engagement of a 3'-phosphate terminus may block access of a 5'-hydroxyl to the kinase active site	723644	
2.7.1.78	physiological function	degradation of RegB-cleaved mRNAs depends on a functional T4 polynucleotide kinase/phosphatase. PNK controls the decay of early transcripts predominantly from their 5'-termini. The 5'-OH produced by RegB cleavage is phosphorylated by the kinase activity of PNK. When the 5'-OH RNA end generated by RegB is not phosphorylated by PNK, the attack by RNases E and G is blocked or decreased over a distance of about 300 nt from the RegB site. But after PNK has modified the 5'-terminus and RNase G (or E) has cut at secondary sites, the new 5'-monophosphorylated RNA ends can presumably activate RNases E and G in cascade. The PNK-dependent pathway of degradation becomes effective 5 min postinfectio. The T4 PNK also has a role during normal phage development	723662	
2.7.1.78	physiological function	mice with PNKP inactivation in neural progenitors manifest neurodevelopmental abnormalities and postnatal death. The phenotype involves defective base excision repair and nonhomologous end-joining. Mice homozygous for the T424GfsX48 frame-shift allele are lethal embryonically, and attenuated PNKP levels akin to microcephaly with seizures syndrome show general neurodevelopmental defects. Directed postnatal neural inactivation of PNKP affects specific subpopulations including oligodendrocytes	750414	
2.7.1.78	physiological function	PNKP stably associates with ataxin-3. Purified wild-type ataxin-3 stimulates, and the mutant form specifically inhibits, PNKP's 3'-phosphatase activity in vitro. ATXN3-deficient cells also show decreased PNKP activity	751906	
2.7.1.78	physiological function	polynucleotide kinase and aprataxin-like forkhead-associated protein (PALF) acts as both a single-stranded DNA endonuclease and a single-stranded DNA 3 exonuclease and can participate in DNA end joining in a biochemical system, they use the forkhead-associated domain to bind to x-ray repair complementing defective repair in Chinese hamster cells 4, XRCC4, overview	722727	
2.7.1.78	physiological function	polynucleotide kinase phosphatase is a DNA repair factor with dual enzymatic functions, i.e., phosphorylation of 5'-end and dephosphorylation of 3'-end, which are prerequisites for DNA ligation and, thus, is involved in multiple DNA repair pathways, i.e., base excision repair, single-strand break repair and double-strand break repair through nonhomologous end joining	762248	
2.7.1.78	physiological function	polynucleotide kinase/phosphatase is an essential enzyme for the repair of damaged DNA termini. PNKP possesses both 5'-kinase and 3'-phosphatase activities that are frequently required for processing of single- and double-strand break termini	716975	
2.7.1.78	physiological function	posphorylation and dephosphorylation of DNA by polynucleotide kinase has an important role in DNA damage repair, replication, and recombination	737431	
2.7.1.78	physiological function	the nonribosomal protein Nol9 is a polynucleotide 5'-kinase that sediments primarily with the pre-60S and pre-40S ribosomal particles in HeLa nuclear extracts. The polynucleotide kinase activity of Nol9 is required for processing of large subunit rRNA and efficient generation of the 5.8S and 28S rRNAs from the 32S precursor	722115