Induction of cellular prion protein gene expression by copper in neurons

Lorena Varela-Nallar, Enrique M. Toledo, Luis F. Larrondo, Ana L B Cabral, Vilma R. Martins, Nibaldo C. Inestrosa

Resultado de la investigación: Article

51 Citas (Scopus)

Resumen

Prion diseases are caused by the conformational transition of the native α-helical cellular prion protein (PrPC) into a β-sheet pathogenic isoform. However, the normal physiological function of PrP C remains elusive. We report herein that copper induces PrP C expression in primary hippocampal and cortical neurons. PrP C induced by copper has a normal glycosylation pattern, is proteinase K-sensitive and reaches the cell surface attached by a glycosyl phosphatidylinositol anchor. Immunofluorescence analysis revealed that copper induces PrPC levels in the cell surface and in an intracellular compartment that we identified as the Golgi complex. In addition, copper induced the activity of a reporter vector driven by the rat PrPC gene (Prnp) promoter stably transfected into PC12 cells, whereas no effect was observed in glial C6 clones. Also cadmium, but not zinc or manganese, upregulated Prnp promoter activity in PC12 clones. Progressive deletions of the promoter revealed that the region essential for copper modulation contains a putative metal responsive element. Although electrophoretic mobility shift assay demonstrated nuclear protein binding to this element, supershift analysis showed that this is not a binding site for the metal responsive transcription factor-1 (MTF-1). The MTF-1-independent transcriptional activation of Prnp is supported by the lack of Prnp promoter activation by zinc. These findings demonstrate that Prnp expression is upregulated by copper in neuronal cells by an MTF-1-independent mechanism, and suggest a metalspecific modulation of Prnp in neurons.

Idioma originalEnglish
PublicaciónAmerican Journal of Physiology - Cell Physiology
Volumen290
N.º1
DOI
EstadoPublished - 1 ene 2006

Huella dactilar

Copper
Gene Expression
Neurons
Zinc
Clone Cells
Endopeptidase K
Glycosylphosphatidylinositols
Prion Diseases
PC12 Cells
Golgi Apparatus
Electrophoretic Mobility Shift Assay
Manganese
Nuclear Proteins
Cadmium
Glycosylation
Genetic Promoter Regions
Protein Binding
Neuroglia
Transcriptional Activation
Fluorescent Antibody Technique

ASJC Scopus subject areas

  • Physiology
  • Cell Biology

Citar esto

Varela-Nallar, Lorena ; Toledo, Enrique M. ; Larrondo, Luis F. ; Cabral, Ana L B ; Martins, Vilma R. ; Inestrosa, Nibaldo C. / Induction of cellular prion protein gene expression by copper in neurons. En: American Journal of Physiology - Cell Physiology. 2006 ; Vol. 290, N.º 1.
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abstract = "Prion diseases are caused by the conformational transition of the native α-helical cellular prion protein (PrPC) into a β-sheet pathogenic isoform. However, the normal physiological function of PrP C remains elusive. We report herein that copper induces PrP C expression in primary hippocampal and cortical neurons. PrP C induced by copper has a normal glycosylation pattern, is proteinase K-sensitive and reaches the cell surface attached by a glycosyl phosphatidylinositol anchor. Immunofluorescence analysis revealed that copper induces PrPC levels in the cell surface and in an intracellular compartment that we identified as the Golgi complex. In addition, copper induced the activity of a reporter vector driven by the rat PrPC gene (Prnp) promoter stably transfected into PC12 cells, whereas no effect was observed in glial C6 clones. Also cadmium, but not zinc or manganese, upregulated Prnp promoter activity in PC12 clones. Progressive deletions of the promoter revealed that the region essential for copper modulation contains a putative metal responsive element. Although electrophoretic mobility shift assay demonstrated nuclear protein binding to this element, supershift analysis showed that this is not a binding site for the metal responsive transcription factor-1 (MTF-1). The MTF-1-independent transcriptional activation of Prnp is supported by the lack of Prnp promoter activation by zinc. These findings demonstrate that Prnp expression is upregulated by copper in neuronal cells by an MTF-1-independent mechanism, and suggest a metalspecific modulation of Prnp in neurons.",
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Induction of cellular prion protein gene expression by copper in neurons. / Varela-Nallar, Lorena; Toledo, Enrique M.; Larrondo, Luis F.; Cabral, Ana L B; Martins, Vilma R.; Inestrosa, Nibaldo C.

En: American Journal of Physiology - Cell Physiology, Vol. 290, N.º 1, 01.01.2006.

Resultado de la investigación: Article

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T1 - Induction of cellular prion protein gene expression by copper in neurons

AU - Varela-Nallar, Lorena

AU - Toledo, Enrique M.

AU - Larrondo, Luis F.

AU - Cabral, Ana L B

AU - Martins, Vilma R.

AU - Inestrosa, Nibaldo C.

PY - 2006/1/1

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N2 - Prion diseases are caused by the conformational transition of the native α-helical cellular prion protein (PrPC) into a β-sheet pathogenic isoform. However, the normal physiological function of PrP C remains elusive. We report herein that copper induces PrP C expression in primary hippocampal and cortical neurons. PrP C induced by copper has a normal glycosylation pattern, is proteinase K-sensitive and reaches the cell surface attached by a glycosyl phosphatidylinositol anchor. Immunofluorescence analysis revealed that copper induces PrPC levels in the cell surface and in an intracellular compartment that we identified as the Golgi complex. In addition, copper induced the activity of a reporter vector driven by the rat PrPC gene (Prnp) promoter stably transfected into PC12 cells, whereas no effect was observed in glial C6 clones. Also cadmium, but not zinc or manganese, upregulated Prnp promoter activity in PC12 clones. Progressive deletions of the promoter revealed that the region essential for copper modulation contains a putative metal responsive element. Although electrophoretic mobility shift assay demonstrated nuclear protein binding to this element, supershift analysis showed that this is not a binding site for the metal responsive transcription factor-1 (MTF-1). The MTF-1-independent transcriptional activation of Prnp is supported by the lack of Prnp promoter activation by zinc. These findings demonstrate that Prnp expression is upregulated by copper in neuronal cells by an MTF-1-independent mechanism, and suggest a metalspecific modulation of Prnp in neurons.

AB - Prion diseases are caused by the conformational transition of the native α-helical cellular prion protein (PrPC) into a β-sheet pathogenic isoform. However, the normal physiological function of PrP C remains elusive. We report herein that copper induces PrP C expression in primary hippocampal and cortical neurons. PrP C induced by copper has a normal glycosylation pattern, is proteinase K-sensitive and reaches the cell surface attached by a glycosyl phosphatidylinositol anchor. Immunofluorescence analysis revealed that copper induces PrPC levels in the cell surface and in an intracellular compartment that we identified as the Golgi complex. In addition, copper induced the activity of a reporter vector driven by the rat PrPC gene (Prnp) promoter stably transfected into PC12 cells, whereas no effect was observed in glial C6 clones. Also cadmium, but not zinc or manganese, upregulated Prnp promoter activity in PC12 clones. Progressive deletions of the promoter revealed that the region essential for copper modulation contains a putative metal responsive element. Although electrophoretic mobility shift assay demonstrated nuclear protein binding to this element, supershift analysis showed that this is not a binding site for the metal responsive transcription factor-1 (MTF-1). The MTF-1-independent transcriptional activation of Prnp is supported by the lack of Prnp promoter activation by zinc. These findings demonstrate that Prnp expression is upregulated by copper in neuronal cells by an MTF-1-independent mechanism, and suggest a metalspecific modulation of Prnp in neurons.

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AN - SCOPUS:33644832483

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JO - American Journal of Physiology - Cell Physiology

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