title: Electrostatic association of glutathione transferase to the nuclear membrane. Evidence of an enzyme defense barrier at the nuclear envelope.
abstract: The possible nuclear compartmentalization of glutathione S-transferase (GST) isoenzymes has been the subject of contradictory reports. The discovery that the dinitrosyl-diglutathionyl-iron complex binds tightly to Alpha class GSTs in rat hepatocytes and that a significant part of the bound complex is also associated with the nuclear fraction (Pedersen, J. Z., De Maria, F., Turella, P., Federici, G., Mattei, M., Fabrini, R., Dawood, K. F., Massimi, M., Caccuri, A. M., and Ricci, G. (2007) J. Biol. Chem. 282, 6364-6371) prompted us to reconsider the nuclear localization of GSTs in these cells. Surprisingly, we found that a considerable amount of GSTs corresponding to 10% of the cytosolic pool is electrostatically associated with the outer nuclear membrane, and a similar quantity is compartmentalized inside the nucleus. Mainly Alpha class GSTs, in particular GSTA1-1, GSTA2-2, and GSTA3-3, are involved in this double modality of interaction. Confocal microscopy, immunofluorescence experiments, and molecular modeling have been used to detail the electrostatic association in hepatocytes and liposomes. A quantitative analysis of the membrane-bound Alpha GSTs suggests the existence of a multilayer assembly of these enzymes at the outer nuclear envelope that could represent an amazing novelty in cell physiology. The interception of potentially noxious compounds to prevent DNA damage could be the possible physiological role of the perinuclear and intranuclear localization of Alpha GSTs.
authors.affiliation: Department of Chemical Sciences and Technologies, University of Rome Tor Vergata, 00133 Rome.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Stella
authors.forename: Valentina
authors.initials: V
authors.lastname: Pallottini
authors.forename: Sandra
authors.initials: S
authors.lastname: Moreno
authors.forename: Silvia
authors.initials: S
authors.lastname: Leoni
authors.forename: Francesca
authors.initials: F
authors.lastname: De Maria
authors.forename: Paola
authors.initials: P
authors.lastname: Turella
authors.forename: Giorgio
authors.initials: G
authors.lastname: Federici
authors.forename: Raffaele
authors.initials: R
authors.lastname: Fabrini
authors.forename: Kutayba F
authors.initials: KF
authors.lastname: Dawood
authors.forename: Mario Lo
authors.initials: ML
authors.lastname: Bello
authors.forename: Jens Z
authors.initials: JZ
authors.lastname: Pedersen
authors.forename: Giorgio
authors.initials: G
authors.lastname: Ricci
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D051549:Glutathione S-Transferase pi / Q000378:metabolism / Q000502:physiology; D005982:Glutathione Transferase / Q000378:metabolism* / Q000502:physiology; D022781:Hepatocytes / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism / Q000502:physiology; D008297:Male; D009685:Nuclear Envelope / Q000737:chemistry / Q000201:enzymology*; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar; D055672:Static Electricity
chemical_list: D007527:Isoenzymes; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; C496558:Gstp1 protein, rat; C119995:glutathione S-transferase alpha