Histidine to aspartate phosphotransferase activity of nm23 proteins: phosphorylation of aldolase C on Asp-319

• Published in: Biochemical journal 2000-03, Vol.346 Pt 3 (3), p.623-630
• Main Authors: Wagner, P D, Vu, N D
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Aspartic Acid - chemistry; Aspartic Acid - metabolism; Brain - enzymology; Cattle; Chromatography, High Pressure Liquid; Electrophoresis, Polyacrylamide Gel; Fructose-Bisphosphate Aldolase - metabolism; Histidine - chemistry; Histidine - metabolism; Humans; Molecular Sequence Data; Monomeric GTP-Binding Proteins - metabolism; Muscles - enzymology; NM23 Nucleoside Diphosphate Kinases; Nucleoside-Diphosphate Kinase - metabolism; Phosphorylation; Phosphotransferases - chemistry; Phosphotransferases - metabolism; Rabbits; Rats; Sequence Homology, Amino Acid; Sodium Cholate - pharmacology; Transcription Factors - metabolism
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/0264-6021:3460623

nm23 genes have been implicated in the suppression of tumour metastasis and cell motility; however, the biochemical mechanisms for these suppressions are not known. We have previously described the transfer of phosphate from the catalytic histidine residues of nm23 proteins to an aspartic or a glutamic residue on one or more 43 kDa proteins in detergent extracts of bovine brain membranes. To gain a better understanding of this transferase activity, we partly purified this 43 kDa protein and identified aldolases A and C as the major 43 kDa proteins present in the preparation. Aldolase was purified from brain cytosol; its phosphorylation by rat liver nm23 proteins and by recombinant human nm23-H1 was examined. The site of phosphorylation was identified as Asp-319 on aldolase C. The equivalent residue on aldolase A, a glutamic residue, was not phosphorylated. Aldolase C was rapidly phosphorylated by wild-type nm23-H1 but was not phosphorylated, or was phosphorylated very slowly, by either nm23-H1(P96S) or nm23-H1(S120G), mutants of nm23-H1 that do not suppress cell motility. This is the first identification of a protein that is phosphorylated on an aspartic residue by nm23 proteins. The sequence around Asp-319 of aldolase C has some similarities to those around the histidine residues on ATP-citrate lyase and succinic thiokinase that are phosphorylated by nm23 proteins.