Transcriptional Repression by the Human Homeobox Protein EVX1 in Transfected Mammalian Cells (*)
- Paola Briata(1)(§),
- Rinke Van De Werken(1),
- Irma Airoldi(1)(¶),
- Cristina Ilengo(1),
- Erica Di Blas(1),
- Edoardo Boncinelli(2) and
- Giorgio Corte(1)(3)
- From the (1) Laboratory of Immunobiology I.S.T., Advanced Biotechnology Center, 16132 Genova, Italy,
- (2) DIBIT H. S. Raffaele, 20132 Milano, Italy, and
- (3) Institute of Biochemistry, Genoa University Medical School, 16132 Genova, Italy
- § To whom correspondence should be addressed: Laboratory of Immunobiology, Advanced Biotechnology Center, Viale R. Benzi, 10, 16132 Genova, Italy. Tel.: 39-10-5737401; Fax: 39-10-5737405.
Abstract
The human homeobox protein EVX1 (EVX1) is thought to play an important role during embryogenesis. In this study, the effect of EVX1 on gene transcription has been investigated in transfected mammalian cells. EVX1 expression represses transcription of a reporter gene directed by either cell-specific or viral promoter/enhancer sequences in a variety of mammalian cell lines and in a concentration-dependent manner. Transcriptional repression is independent of the presence of DNA-binding sites for EVX1 in all the promoters we tested. Furthermore, repression by EVX1 is evident also using a TATA-less minimal promoter in the reporter construct. A carboxyl-terminal proline/alanine-rich region of EVX1 seems to be responsible for the transcriptional repression activity, as suggested by transfection of EVX1 mutants. We speculate that the repressor function of EVX1 contributes to its proposed role in embryogenesis.
Footnotes
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↵¶ Recipient of an AIRC fellowship.
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↵* This work was partially supported by grants from AIRC, MURST, and Ministero della Sanità (to G. C.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵1 The abbreviations used are:
- HD
-
homeodomain
- TRE
-
12-O-tetradecanoylphorbol 13-acetate response element
- EVX1
-
human homeobox protein EVX1
- CAT
-
chloramphenicol acetyltransferase
- DEAE-dextran
-
diethylaminoethyl-dextran
- PCR
-
polymerase chain reaction
- RT-PCR
-
reverse transcriptase-PCR
- Eve
-
even-skipped product
- mAb
-
monoclonal antibody
- bp
-
base pair(s).
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↵3 Antonio Daga and G. Corte, submitted for publication.
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↵4 P. Briata and G. Corte, unpublished results.
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- Received August 10, 1995.
- © 1995 by The American Society for Biochemistry and Molecular Biology, Inc.
