title: Location of NRAMP1 molecule on the plasma membrane and its association with microtubules.
abstract: Natural resistance to infection with intracellular parasites, such as Leishmania, Salmonella, and Mycobacterium, is controlled in mice by the expression of a single dominant gene locus designated Lsh/Ity/Bcg. Natural resistance-associated macrophage protein gene 1 (NRAMP1) was isolated as a candidate gene. NRAMP1 encodes an M(r) 60000 polypeptide with 10-12 potential transmembrane domains and an evolutionary conserved consensus transport motif. The present study shows that the human NRAMP1 molecule is expressed in all cell lineages of macrophage/monocyte and B- and T-lymphocytes. Immunohistochemical analysis using antihuman NRAMP1 antibody provides the direct evidence that the NRAMP1 molecule is located and distributed on the plasma membrane. An NRAMP1-glutathione S-transferase (GST) fusion protein was used to affinity-purify a protein, bound to the NH2-terminal cytoplasmic domain of NRAMP1. It was found that the NRAMP1 molecule was associated with alpha- and beta-tubulin of microtubules. These results suggest that NRAMP1 may function as a molecule, possessing the abilities of membrane-anchoring and microtubule-binding, for the microtubule-mediated transport of vesicles and be a new class of microtubule-associated proteins.
authors.affiliation: Center for Gene Research, Yamaguchi University, Ube, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Kishi
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.forename: S
authors.initials: S
authors.lastname: Aiso
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism; D027682:Cation Transport Proteins; D002462:Cell Membrane / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D013347:Subcellular Fractions / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D014404:Tubulin / Q000737:chemistry; D014407:Tumor Cells, Cultured; D000099173:Natural Resistance-associated Macrophage Protein 1
chemical_list: D002352:Carrier Proteins; D027682:Cation Transport Proteins; D008565:Membrane Proteins; D014404:Tubulin; D000099173:Natural Resistance-associated Macrophage Protein 1