Two-component kinase-like activity of nm23 correlates with its motility-suppressing activity.
Nm23 genes, which encode nucleoside diphosphate kinases, have been implicated in suppressing tumor metastasis. The motility of human breast carcinoma cells can be suppressed by transfection with wild-type nm23-H1, but not by transfections with two nm23-H1 mutants, nm23-H1(S12OG) and nm23-H1(P96S). Here we report that nm23-H1 can transfer a phosphate from its catalytic histidine to aspartate or glutamate residues on 43-kDa membrane proteins. One of the 43-kDa membrane proteins was not phosphorylated by either nm23-H1(P96S) or nm23-H1(S120G), and another was phosphorylated much more slowly by nm23-H1(P96S) and by nm23-H1(S120G) than by wild-type nm23-H1. Nm23-H1 also can transfer phosphate from its catalytic histidine to histidines on ATP-citrate lyase and succinic thiokinase. The rates of phosphorylation of ATP-citrate lyase by nm23-H1(S120G) and nm23-H1(P96S) were similar to that by wild-type nm23-H1. The rate of phosphorylation of succinic thiokinase by nm23-H1(S120) was similar to that by wild-type nm23-H1, and the rate of phosphorylation of succinic thiokinase by nm23-H1(P96S) was about half that by wild-type nm23-H1. Thus, the transfer of phosphate from nm23-H1 to aspartates or glutamates on other proteins appears to correlate better with the suppression of motility than does the transfer to histidines.
Wagner
P D
PD
Laboratory of Biochemistry, Division of Basic Sciences, National Cancer Institute, Bethesda, MD 20892, USA. wagnerp@dc37a.nci.nih.gov
Steeg
P S
PS
Vu
N D
ND
D000818:Animals; D002465:Cell Movement / Q000235:genetics*; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D006801:Humans; D008099:Liver / Q000201:enzymology; D020559:Monomeric GTP-Binding Proteins; D054778:NM23 Nucleoside Diphosphate Kinases; D009701:Nucleoside-Diphosphate Kinase / Q000235:genetics* / Q000378:metabolism; D016716:PC12 Cells; D010766:Phosphorylation; D051381:Rats; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D054778:NM23 Nucleoside Diphosphate Kinases; D014157:Transcription Factors; C517938:NME1 protein, human; D009701:Nucleoside-Diphosphate Kinase; D020559:Monomeric GTP-Binding Proteins