title: Spermine induced phosphorylation of a 42 kD/pI 5.9 nuclear protein in different human tumor cell lines.
abstract: In vitro phosphorylation of 5 M urea extracts from nuclei obtained from different human tumor cell lines leads to incorporation of phosphate from 32P-gamma-ATP in more than 20 polypeptides with an acidic pI. Whereas heparin at a concentration of 1 microgram had no effect on the phosphorylation pattern, spermine stimulated the total phosphorylation up to twofold. Furthermore, in the presence of this polyamine, the two-dimensional polyacrylamide gel revealed an additional phosphoprotein with an apparent pI of 5.9 and a relative molecular mass of 42 000. Phosphoamino acid analysis of the most prominent phosphoproteins showed serine and threonine as phosphoacceptors.
authors.forename: G
authors.initials: G
authors.lastname: Unteregger
mesh_terms: D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005354:Fibrosarcoma / Q000378:metabolism*; D005909:Glioblastoma / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D007526:Isoelectric Point; D008970:Molecular Weight; D009698:Nucleoproteins / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D013096:Spermine / Q000494:pharmacology*
chemical_list: D009698:Nucleoproteins; D010710:Phosphates; D010750:Phosphoproteins; D013096:Spermine; D006493:Heparin; D011494:Protein Kinases