Differential Localization of Divalent Metal Transporter 1 with and without Iron Response Element in Rat PC12 and Sympathetic Neuronal Cells
Open Access
- 15 October 2000
- journal article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 20 (20), 7595-7601
- https://doi.org/10.1523/jneurosci.20-20-07595.2000
Abstract
Two isoforms of divalent metal transporter 1 (DMT1) (Nramp2 and DCT1) are encoded by two mRNA species, one of which contains an iron response element (IRE) motif in the 3′-noncoding region. The subcellular distribution of the two isoforms of DMT1 is distinct, and the −IRE species accumulates in the nucleus of neuronal or neuronal-like cells. Reverse transcription-PCR and Western blot analysis of PC12 cells reveals that these cells express both forms of DMT1. Immunofluorescence and immunoblotting studies, using immunospecific antibodies to the −IRE form of DMT1, demonstrate that this form of the transporter, in PC12 cells, is predominantly localized in the nucleus, cell membrane, and neurites with only weak staining of the cell body. Studies using antibodies to the +IRE form indicate that this species of DMT1 is distributed within vesicles in the cell body and neurite projections, with minimal nuclear staining. Similar staining patterns are observed for the two forms of DMT1 in cultures of sympathetic ganglion neurons isolated from perinatal rat pups. To determine whether nuclear localization of the −IRE form of DMT1 is constrained to neuronal or neuronal-like cells, immunocytochemical studies were performed with human embryonic kidney 293T (HEK293T), HEP2G hepatoma and medulloblastoma, and rat Schwann cells. The −IRE-specific antibodies stained nuclei from medulloblastoma, whereas little nuclear staining was observed with HEK293T, hepatoma, or Schwann cells. The unexpected finding that the −IRE species of DMT1 selectively accumulates in the nucleus of neuronal and neuronal-like cells leads us to postulate that the two proteins may have different functionsin vivo.Keywords
This publication has 29 references indexed in Scilit:
- Regulation of Genes of Iron Metabolism by the Iron-Response ProteinsThe American Journal of the Medical Sciences, 1999
- Manganese induces apoptosis of human B cells: caspase-dependent cell death blocked by Bcl-2Cell Death & Differentiation, 1999
- Iron regulatory protein as an endogenous sensor of iron in rat intestinal mucosaEuropean Journal of Biochemistry, 1999
- The Human Nramp2 Gene: Characterization of the Gene Structure, Alternative Splicing, Promoter Region and PolymorphismsBlood Cells, Molecules, and Diseases, 1998
- Membrane Localization of cAMP-dependent Protein Kinase Amplifies cAMP Signaling to the Nucleus in PC12 CellsPublished by Elsevier BV ,1996
- Manganese and 1-methyl-4-(2′-ethylphenyl)-1,2,3,6-tetrahydropyridine induce apoptosis in PC12 cellsNeuroscience Letters, 1996
- Identification and characterization of a second mouse Nramp geneGenomics, 1995
- Manganese Transport and Na/K/Cl Cotransport in PC‐12 CellaAnnals of the New York Academy of Sciences, 1993
- Manganese induces spreading and process outgrowth in rat pheochromocytoma (PC12) cellsJournal of Neuroscience Research, 1993
- Colocalization of synaptophysin with transferrin receptors: implications for synaptic vesicle biogenesis.The Journal of cell biology, 1991