title: Metabolism of 4-pyridone-3-carboxamide-1-beta-D-ribonucleoside triphosphate and its nucleoside precursor in the erythrocytes.
abstract: We recently discovered new nucleotides (4-pyridone-3-carboxamide-1-beta -D-ribonucleoside phosphates) in human erythrocytes. To establish the precursor compound and pathways of nucleotide derivative formation and breakdown, human erythrocytes were incubated for 3 hours with 0.3 mM 4-pyridone-3-carboxamide-1-beta-D-ribonucleoside (4PYR) and erythrocyte concentrations of 4PYR and adenine nucleotides were followed. 4PYR triphosphate increased from 16.1 +/- 0.6 micro M to 74.9 +/- 9.17 and 4PYR monophosphate increased from 5 micro M to 254.7 +/- 13.9 micro M. Conversely, incubation with 0.3 mM 4-pyridone-3-carboxamide (4PY) did not lead to additional 4PYR nucleotide formation. 4PYR nucleotides were catabolized to 4PYR. We conclude that 4PYR nucleotides are formed in erythrocytes by nucleoside kinase-mediated 4PYR phosphorylation and catabolized by 5'nucleotidase-mediated dephosphorylation.
authors.affiliation: Department of Biochemistry, Medical University of Gdansk, Gdansk, Poland.
authors.forename: E M
authors.initials: EM
authors.lastname: Slominska
authors.forename: C
authors.initials: C
authors.lastname: Orlewska
authors.forename: A
authors.initials: A
authors.lastname: Yuen
authors.forename: L
authors.initials: L
authors.lastname: Osman
authors.forename: P
authors.initials: P
authors.lastname: Romaszko
authors.forename: E
authors.initials: E
authors.lastname: Sokolowska
authors.forename: H
authors.initials: H
authors.lastname: Foks
authors.forename: H A
authors.initials: HA
authors.lastname: Simmonds
authors.forename: M H
authors.initials: MH
authors.lastname: Yacoub
authors.forename: R T
authors.initials: RT
authors.lastname: Smolenski
mesh_terms: D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D007185:Incubators; D009705:Nucleosides / Q000097:blood* / Q000737:chemistry / Q000378:metabolism*; D009711:Nucleotides / Q000097:blood* / Q000378:metabolism*; D013997:Time Factors
chemical_list: C516364:4-pyridone-3-carboxamide N-1 riboside triphosphate; D009705:Nucleosides; D009711:Nucleotides