title: Nuclear localization and DNA interaction of protein disulfide isomerase ERp57 in mammalian cells.
abstract: Protein disulfide isomerase ERp57 is localized predominantly in the endoplasmic reticulum, but is also present in the cytosol and, according to preliminary evidence, in the nucleus of avian cells. Conclusive evidence of its nuclear localization and of its interaction with DNA in vivo in mammalian cells is provided here on the basis of DNA-protein cross-linking experiments performed with two different cross-linking agents on viable HeLa and 3T3 cells. Nuclear ERp57 could also be detected by immunofluorescence in HeLa cells, where it showed an intracellular distribution clearly different from that of an homologous protein, located exclusively in the endoplasmic reticulum. Mammalian ERp57 resembles the avian protein in its recognition of S/MAR-like DNA sequences and in its association with the nuclear matrix. It can be hypothesized that ERp57, which is known to associate with other proteins, in particular STAT3 and calreticulin, may contribute to their nuclear import, DNA binding, or other functions that they fulfil inside the nucleus.
authors.affiliation: Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'Alessandro Rossi-Fanelli' and Centro di Biologia Molecolare del CNR, Università 'La Sapienza', Rome, Italy.
authors.forename: Sabina
authors.initials: S
authors.lastname: Coppari
authors.forename: Fabio
authors.initials: F
authors.lastname: Altieri
authors.forename: Anna
authors.initials: A
authors.lastname: Ferraro
authors.forename: Silvia
authors.initials: S
authors.lastname: Chichiarelli
authors.forename: Margherita
authors.initials: M
authors.lastname: Eufemi
authors.forename: Carlo
authors.initials: C
authors.lastname: Turano
mesh_terms: D016475:3T3 Cells / Q000378:metabolism / Q000528:radiation effects; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000378:metabolism; D037282:Calreticulin; D002467:Cell Nucleus / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000378:metabolism; D004273:DNA, Neoplasm / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005455:Fluorescent Antibody Technique; D018922:HL-60 Cells / Q000378:metabolism; D006367:HeLa Cells / Q000378:metabolism / Q000528:radiation effects; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007535:Isomerases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D051379:Mice; D018832:Molecular Chaperones / Q000378:metabolism; D015530:Nuclear Matrix / Q000201:enzymology*; D019704:Protein Disulfide-Isomerases; D012261:Ribonucleoproteins / Q000378:metabolism; D050796:STAT3 Transcription Factor; D013347:Subcellular Fractions; D013552:Swine; D015534:Trans-Activators / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D002135:Calcium-Binding Proteins; D037282:Calreticulin; D003432:Cross-Linking Reagents; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D012261:Ribonucleoproteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C494087:Stat3 protein, mouse; D015534:Trans-Activators; D007535:Isomerases; C513195:Pdia3 protein, mouse; D019704:Protein Disulfide-Isomerases; C085868:PDIA3 protein, human