title: Identification of structural domains affecting transactivation potential of Nm23.
abstract: The strong transactivation activity of the C-terminal half (amino acids 76-152) of Nm23 was reported previously. Here we examined a structural domain preventing or necessary to its transactivation activity. The C-terminal 1/4 (amino acids 109-152) was sufficient for transactivation, but the C-terminal half with a longer N-terminal extension (amino acids 58-152) caused the loss of the transactivation ability. Furthermore, coexpression of the N-terminal half with the C-terminus of Nm23-H1 blocked the transactivation activity of the C-terminal half, where direct interaction of both truncated proteins was demonstrated in vitro. Transactivation activities in the C-terminal halves of the known mutants (P96S, H118F, S120G, and S120A) exhibiting differential antimetastasis effects were also tested. Significant reduction of transactivation activity was observed only in H118F, indicating that NPD kinase active-site histidine is required. This suggests that transactivation potential of Nm23 is related to NDP kinase activity but not to metastasis suppressor activity.
authors.affiliation: Research Center for Bio-medicinal Resources, Paichai University, 439-6 Doma-dong, Seo-gu, Taejon 302-735, South Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Cho
authors.forename: N S
authors.initials: NS
authors.lastname: Lee
authors.forename: Y S
authors.initials: YS
authors.lastname: Jung
authors.forename: H
authors.initials: H
authors.lastname: Lee
authors.forename: K J
authors.initials: KJ
authors.lastname: Lee
authors.forename: E
authors.initials: E
authors.lastname: Kim
authors.forename: S K
authors.initials: SK
authors.lastname: Chae
mesh_terms: D001665:Binding Sites; D017930:Genes, Reporter; D006639:Histidine / Q000235:genetics; D006801:Humans; D020559:Monomeric GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D054778:NM23 Nucleoside Diphosphate Kinases; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology; D009701:Nucleoside-Diphosphate Kinase / Q000737:chemistry; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion; D015534:Trans-Activators / Q000737:chemistry / Q000502:physiology; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D015533:Transcriptional Activation; D014170:Transformation, Genetic; D015003:Yeasts / Q000235:genetics
chemical_list: D054778:NM23 Nucleoside Diphosphate Kinases; D015534:Trans-Activators; D014157:Transcription Factors; D006639:Histidine; C517938:NME1 protein, human; D009701:Nucleoside-Diphosphate Kinase; D020559:Monomeric GTP-Binding Proteins