title: Direct interaction between NM23-H1 and macrophage migration inhibitory factor (MIF) is critical for alleviation of MIF-mediated suppression of p53 activity.
abstract: Macrophage migration inhibitory factor (MIF) is a pluripotent cytokine that is involved in host immune and inflammatory responses, as well as tumorigenesis. However, the regulatory mechanism of MIF function is unclear. Here we report that the NM23-H1 interacts with MIF in cells, as demonstrated by cotransfection and coimmunoprecipitation experiments. Analysis of cysteine (Cys) to serine (Ser) substitution mutants of NM23-H1 (C4S, C109S, and C145S) and MIF (C57S, C60S, and C81S) revealed that Cys(145) of NM23-H1 and Cys(60) of MIF are responsible for complex formation. NM23-H1-MIF complexes were dependent on reducing conditions, such as the presence of dithiothreitol or beta-mercaptoethanol, but not H(2)O(2). NM23-H1 alleviated the MIF-mediated suppression of p53-induced apoptosis and cell cycle arrest by promoting the dissociation of MIF from MIF-p53 complexes. In addition, NM23-H1 significantly inhibited the MIF-induced proliferation of quiescent NIH 3T3 cells through a direct interaction with MIF, and decreased the MIF-induced activation of phosphatidylinositol 3-kinase/PDK1 and p44/p42 extracellular signal-regulated (ERK) mitogen-activated protein kinase. The results of the current study suggest that the NM23-H1 functions as a negative regulator of MIF.
authors.affiliation: Department of Biochemistry, Biotechnology Research Institute, School of Life Sciences, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors.forename: Haiyoung
authors.initials: H
authors.lastname: Jung
authors.forename: Hyun-A
authors.initials: HA
authors.lastname: Seong
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Ha
mesh_terms: D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D003545:Cysteine / Q000737:chemistry; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D008263:Macrophage Migration-Inhibitory Factors / Q000378:metabolism*; D008623:Mercaptoethanol / Q000737:chemistry; D051379:Mice; D008954:Models, Biological; D041681:NIH 3T3 Cells; D054778:NM23 Nucleoside Diphosphate Kinases / Q000378:metabolism / Q000502:physiology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D008263:Macrophage Migration-Inhibitory Factors; D054778:NM23 Nucleoside Diphosphate Kinases; D016159:Tumor Suppressor Protein p53; D008623:Mercaptoethanol; D006861:Hydrogen Peroxide; D048049:Extracellular Signal-Regulated MAP Kinases; C517938:NME1 protein, human; D003545:Cysteine