Differential distribution of the adenovirus E1A proteins and colocalization of E1A with the 70-kilodalton cellular heat shock protein in infected cells

White, E., Spector, D. L., Welch, W. (November 1988) Differential distribution of the adenovirus E1A proteins and colocalization of E1A with the 70-kilodalton cellular heat shock protein in infected cells. Journal of Virology, 62 (11). pp. 4153-66. ISSN 0022-538X

Abstract

Five distinct localization patterns were observed for the adenovirus E1A proteins in the nuclei of infected HeLa cells: diffuse, reticular, nucleolar, punctate, and peripheral. The variable distribution of E1A was correlated with the time postinfection and the cell cycle stage of the host cell at the time of infection. All staining patterns, with the exception of peripheral E1A localization, were associated with the early phase of infection since only the diffuse, reticular, nucleolar, and punctate staining patterns were observed in the presence of hydroxyurea. Because the E1A proteins (12S and 13S) stimulate the expression of the cellular heat shock 70-kilodalton protein (hsp70), we examined the intracellular distribution of hsp70 in the adenovirus-infected cells. Whereas hsp70 was predominantly cytoplasmic in the cells before infection, after adenovirus infection most of the protein was now found within the nucleus. Specifically, hsp70 was found within the nucleoli as well as exhibiting reticular, diffuse, and punctate nuclear staining patterns, analogous to those observed for the E1A proteins. Double-label indirect immunofluorescence of E1A and hsp70 in infected cells demonstrated a colocalization of these proteins in the nucleus. Translocation of hsp70 to the nucleus was dependent upon both adenovirus infection and expression of the E1A proteins. The localization of hsp70 was unaltered by infection with an E1A 9S cDNA virus which does not synthesize a functional E1A gene product. Moreover, the discrete nuclear localization patterns of E1A and the colocalization of E1A with hsp70 were not observed in adenovirus-transformed 293 cells which constitutively express E1A and E1B. E1A displayed exclusively diffuse nuclear staining in 293 cells; however, localization of E1A into the discrete nuclear patterns occurred after adenovirus infection of 293 cells. Immunoprecipitation of labeled infected-cell extracts with a monoclonal antibody directed against the E1A proteins resulted in precipitation of small amounts of hsp70 along with E1A. These data indicate that the adenovirus E1A proteins colocalize with, and possibly form a physical complex with, cellular hsp70 in infected cells. The relevance of this association, with respect to the function of these proteins during infection and the association of other oncoproteins with hsp70, is discussed.

Item Type: Paper
Additional Information:
Uncontrolled Keywords: Adenoviridae metabolism Adenovirus Early Proteins Antibodies Monoclonal diagnostic use Cell Line Transformed Cell Nucleus analysis Comparative Study Flow Cytometry Fluorescent Antibody Technique Heat-Shock Proteins analysis metabolism Hela Cells Humans Microscopy Fluorescence Oncogene Proteins Viral analysis/metabolism Precipitin Tests
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > E1A protein
organism description > virus
CSHL Authors:
Communities: CSHL labs > Spector lab
Depositing User: Brian Soldo
Date: November 1988
Date Deposited: 30 Mar 2012 22:43
Last Modified: 29 Jan 2015 20:48
Related URLs:
URI: https://repository.cshl.edu/id/eprint/25774

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