Role of adenovirus E1B proteins in transformation: altered organization of intermediate filaments in transformed cells that express the 19-kilodalton protein

White, E., Cipriani, R. (January 1990) Role of adenovirus E1B proteins in transformation: altered organization of intermediate filaments in transformed cells that express the 19-kilodalton protein. Molecular and Cellular Biology, 10 (1). pp. 120-130. ISSN 0270-7306

Abstract

Cooperation of the nuclear oncogene E1A with the E1B oncogene is required for transformation of primary cells. Expression vectors were constructed to produce the 19-kilodalton (19K) and 55K E1B proteins under the direction of heterologous promoters in order to investigate the role of individual E1B proteins in transformation. Coexpression of E1A and either the 19K or 55K E1B gene products was sufficient for the formation of transformed foci in primary rat cells at half the frequency of an intact E1B gene, suggesting that the 19K and 55K proteins function via independent pathways in transformation. Furthermore, the effects of Ha-ras and the E1B 19K gene product were additive when cotransfected with E1A, suggesting that the 19K protein functions in transformation by a mechanism independent from that of ras as well. Although expression of E1A and either E1B protein was sufficient for the subsequent growth of cells in long-term culture, the 19K protein was required to support growth in semisolid media. As the 19K protein has been shown to associate with and disrupt intermediate filaments (IFs) when transiently expressed with plasmid vectors (E. White and R. Cipriani, Proc. Natl. Acad. Sci. USA, 86:9886-9890, 1989), the organization of IFs in transformed cells was investigated. Primary rat cells transformed by plasmids encoding E1A plus the E1B 19K protein showed gross perturbations of IFs, whereas cell lines transformed by plasmids encoding E1A plus the E1B 55K protein or E1A plus Ha-ras did not. These results suggest that an intact IF cytoskeleton may inhibit anchorage-independent growth and that the E1B 19K protein can overcome this inhibition by disrupting the IF cytoskeleton.

Item Type: Paper
Uncontrolled Keywords: Adenovirus Early Proteins *Adenoviruses, Human Animals Cell Division Cell Transformation, Neoplastic/*pathology *Cell Transformation, Viral Cloning, Molecular Cytoskeleton/*ultrastructure Genetic Vectors Intermediate Filaments/*ultrastructure Oncogene Proteins, Viral/*physiology *Oncogenes Rats Research Support, U.S. Gov't, P.H.S. Transfection
Subjects: organism description > virus > adenovirus
organs, tissues, organelles, cell types and functions > cell types and functions > cell functions > cell division
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > genes, structure and function > genes: types > oncogene
Investigative techniques and equipment > transfection
CSHL Authors:
Communities: CSHL labs
Depositing User: Matt Covey
Date: January 1990
Date Deposited: 15 Mar 2016 20:00
Last Modified: 15 Mar 2016 20:00
PMCID: PMC360719
Related URLs:
URI: https://repository.cshl.edu/id/eprint/32328

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