Immunological identification of two adenovirus 2-induced early proteins possibly involved in cell transformation

Gilead, Zvee; Jeng, Yun Hua; Wold, William S.M.; Sugawara, Kenji; Rho, Hyune Mo; Harter, Marian L.; Green, Maurice

doi:10.1038/264263a0

Cited by 154 publications

(66 citation statements)

References 13 publications

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“…Tissue culture cells were harvested and lysed in radioimmunoprecipitation assay (RIPA) buffer (15). Particulate material was removed by centrifugation at 16,000 ϫ g in a microcentrifuge for 10 min at 4°C.…”

Section: Methodsmentioning

confidence: 99%

The Homeodomain Protein CDP Regulates Mammary-Specific Gene Transcription and Tumorigenesis

Zhu

Maitra

Johnston

et al. 2004

Molecular and Cellular Biology

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The CCAAT-displacement protein (CDP) has been implicated in developmental and cell-type-specific regulation of many cellular and viral genes. We previously have shown that CDP represses mouse mammary tumor virus (MMTV) transcription in tissue culture cells. Since CDP-binding activity for the MMTV long terminal repeat declines during mammary development, we tested whether binding mutations could alter viral expression. Infection of mice with MMTV proviruses containing CDP binding site mutations elevated viral RNA levels in virgin mammary glands and shortened mammary tumor latency. To determine if CDP has direct effects on MMTV transcription rather than viral spread, virgin mammary glands of homozygous CDP-mutant mice lacking one of three Cut repeat DNA-binding domains (⌬CR1) were examined by reverse transcription-PCR. RNA levels of endogenous MMTV as well as ␣-lactalbumin and whey acidic protein (WAP) were elevated. Heterozygous mice with a different CDP mutation that eliminated the entire C terminus and the homeodomain (⌬C mice) showed increased levels of MMTV, ␤-casein, WAP, and ␣-lactalbumin RNA in virgin mammary glands compared to those from wild-type animals. No differences in amounts of WDNM1, -casein, or glyceraldehyde-3-phosphate dehydrogenase RNA were observed between the undifferentiated mammary tissues from wild-type and mutant mice, indicating the specificity of this effect. These data show independent contributions of different CDP domains to negative regulation of differentiation-specific genes in the mammary gland.The CCAAT displacement protein (CDP) family constitutes a highly conserved group of homeoproteins that are involved in cell growth, differentiation, and development. CDP (also known as Cut in Drosophila melanogaster, Clox in dogs, and Cux in mice) is a transcriptional repressor that contains four DNA-binding domains, three Cut repeats (CR1, -2, and -3), and a homeodomain (32). CDP is involved in suppressing transcription from many cellular genes, including c-myc, transforming growth factor ␤ type II receptor, phox, CD8, immunoglobulin heavy chain, and T-cell receptor ␤-chain (3,7,12,19,22,46), as well as viral genes, including those from mouse mammary tumor virus (MMTV) and human papillomaviruses (HPVs) (1, 55). In addition, CDP has been implicated as a tumor suppressor gene in human breast carcinomas and uterine leiomyomas (28,47,53).Many genes regulated by CDP are expressed in highly differentiated cells. CDP DNA-binding activity is downregulated during B-cell and myeloid cell development (22, 46), and CDP expression in the kidney is inversely related to the degree of cellular differentiation (44). We have shown that CDP is a repressor of MMTV long terminal repeat (LTR) reporter gene expression in cultured cell lines and that CDP-binding activity to the LTR declines during mammary gland development (55).These results suggest that CDP functions as a transcriptional repressor that inhibits expression of differentiation-specific genes in several tissues.The retrovirus MMTV is a paradigm fo...

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Section: Methodsmentioning

confidence: 99%

The Homeodomain Protein CDP Regulates Mammary-Specific Gene Transcription and Tumorigenesis

Zhu

Maitra

Johnston

et al. 2004

Molecular and Cellular Biology

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“…Other polyclonal antibodies against GST-SATB1 or GST-CDP (CR2-Cterm) (39) were prepared by immunization of rabbits in accordance with the standard procedures of Cocalico Biologicals, Reamstown, Pa. Antibodies were shown to be specific for CDP or SATB1 as described previously (40). Western blots were prepared by lysis of cells in RIPA buffer (25 mM Tris-HCl [pH 7.8], 150 mM NaCl, 2 mM EDTA, 0.5% NP-40, 0.5% deoxycholate, 0.1% SDS) (23). All subsequent steps were performed at room temperature.…”

Section: Methodsmentioning

confidence: 99%

CDP Is a Repressor of Mouse Mammary Tumor Virus Expression in the Mammary Gland

Zhu

Gregg

Lozano

et al. 2000

J Virol

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“…Consequently, we have attempted to identify the ASV src gene product assuming nothing about its mechanism of action. Two approaches have been used in our search, the translation in vitro of the region of the ASV genome that encompasses the src gene using the mRNA-dependent reticulocyte lysate system (13), and use of the strategy successful in identification of simian virus 40, polyoma, and adenovirus T antigens, namely, that animals that carry tumors induced by those viruses produce antibody to nonstructural virus-encoded polypeptides (14)(15)(16)(17)(18) (20). Chick embryo fibroblasts were infected with nd or td SR-ASV and the infected cells were subcultured twice.…”

mentioning

confidence: 99%

Identification of a polypeptide encoded by the avian sarcoma virus src gene.

Purchio¹,

Erikson²,

Brugge³

et al. 1978

Proc. Natl. Acad. Sci. U.S.A.

224

102

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Two techniques were used to search for the polypeptide encoded by the avian sarcoma virus (ASV) src gene. First, antiserum from rabbits bearing ASV-induced fibrosarcomas was used to immunoprecipitate a transformation-specific antigen from ASV-transformed chick embryo fibroblasts. This antigen has an apparent molecular weight (Mr) of 60,000. Second, the 3' one-third of the ASV genome, selected by oligo(dTcellulose chromatography and sucrose gradient sedimentation, was translated in a mRNA-dependent reticulocyte cell-free lysate. This RNA species programmed the synthesis of a polypeptide that comigrated with the transformation-specific antigen of Mr 60,000 immunoprecipitated from transformed cells. The methionine-containing tryptic peptides from the polypeptides of Mr 60,000 obtained from translation in vitro and from immunoprecipitation were found to be identical upon twodimensional fractionation.Some RNA-containing tumor viruses are able to cause rapid and efficient transformation of cells in culture as well as the production of sarcomas in animals. The avian sarcoma viruses (ASV) are particularly interesting because they produce tumors in both avian and mammalian species (1, 2). The high efficiency of cell transformation by these viruses, the availability of viral mutants, and the considerable structural information about the viral genome make ASV useful for the study of the molecular events that occur during viral oncogenesis.Although analyses of viral mutants indicate that a polypeptide encoded by the src gene of ASV is likely to be responsible for the maintenance of cell transformation, such a polypeptide had not been identified biochemically or immunologically when we began our studies. Several ASV conditional, temperature-sensitive (ts) mutants, and nonconditional, deletion mutants, termed transformation-defective (td), have been isolated that have an altered capacity to transform cells (3-5). Studies with ts mutant-infected cells indicate that a virus-encoded product affects gross cytoskeletal structure, growth in soft agar, and rate of sugar uptake, characteristics that are phenotypic markers of transformation in culture. Avian or mammalian cells infected with a ts mutant can be reversibly switched to either the transformed or "normal" state within a few-hours after the appropriate temperature shift. Inhibitors of protein synthesis do not affect the conversion from the transformed to normal state upon shift to the nonpermissive temperature, but do interfere with the appearance of the transformed phenotype when cultures are shifted from the nonpermissive to permissive temperature. These virus mutants can replicate normally at both temperatures, suggesting that a virus-encoded, heat-labile protein, which is not an essential structural component of the virus, is responsible for cell transformation (6).All ts transformation mutations occur in a region of the ASVThe costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "...

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Immunological identification of two adenovirus 2-induced early proteins possibly involved in cell transformation

Cited by 154 publications

References 13 publications

The Homeodomain Protein CDP Regulates Mammary-Specific Gene Transcription and Tumorigenesis

The Homeodomain Protein CDP Regulates Mammary-Specific Gene Transcription and Tumorigenesis

CDP Is a Repressor of Mouse Mammary Tumor Virus Expression in the Mammary Gland

Identification of a polypeptide encoded by the avian sarcoma virus src gene.

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