title: Nuclear localization of glyceraldehyde-3-phosphate dehydrogenase is not involved in the initiation of apoptosis induced by 1-Methyl-4-phenyl-pyridium iodide (MPP+).
abstract: Nuclear localization of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is implicated in the process of apoptosis. To study the function of GAPDH, we expressed GAPDH C-terminally fused with or without nuclear localization signal (NLS) in SH-SY5Y and NB41A3 cells using a retrovirus expression system. GAPDH carrying NLS (GAPDH-NLS) was expressed mainly in the nucleus. However, expression of GAPDH-NLS did not cause any difference in cell survival rate as compared to that of the vector alone or GAPDH without NLS. Treatment with 1-Methyl-4-phenyl-pyridium iodide (MPP+) caused no difference in the cell survival rate or in the pattern or extent of apoptosis among the three transductants. In the cells expressing GAPDH without NLS, MPP+ did not cause visible translocation of GAPDH into nucleus before the onset of apoptosis. Since GAPDH is known to comprise a CRM1-mediated nuclear export signal, we blocked the nuclear export of GAPDH by treatment with leptomycin B, an inhibitor of CRM1-mediated nuclear export. The treatment did not cause any difference in apoptosis among the three transductants. An additional treatment with MPP+ induced no apoptotic difference in these cells. Thus, we have concluded that a simple nuclear localization of GAPDH does not induce apoptosis, and that MPP+-induced apoptosis is not caused by nuclear translocation of GAPDH.
authors.affiliation: Department of Neurology, Institute of Advanced Medicine, Wakayama Medical University, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Kodama
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Kondo
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yokote
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Jing
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sawada
authors.forename: Masaya
authors.initials: M
authors.lastname: Hironishi
authors.forename: Kazushige
authors.initials: K
authors.lastname: Sakaguchi
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000378:metabolism / Q000494:pharmacology*; D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology*; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D042967:Electron Transport Complex I / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000378:metabolism / Q000494:pharmacology; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D028884:Karyopherins / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000378:metabolism; D000097606:Exportin 1 Protein
chemical_list: D015655:1-Methyl-4-phenylpyridinium; D042967:Electron Transport Complex I; D004791:Enzyme Inhibitors; D005231:Fatty Acids, Unsaturated; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D028884:Karyopherins; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D000097606:Exportin 1 Protein; C038753:leptomycin B