A Novel Double-stranded RNA-binding Protein, Disco Interacting Protein 1 (DIP1), Contributes to Cell Fate Decisions during Drosophila Development*
- Dorothy DeSousa‡,
- Mahua Mukhopadhyay‡§,
- Peter Pelka‡¶,
- Xiaoli Zhao‡,
- Bijan K. Dey‡,
- Valérie Robert∥**,
- Alain Pélisson∥,
- Alain Bucheton∥ and
- Ana Regina Campos‡‡‡
- ‡Department of Biology, McMaster University, Hamilton, Ontario L8S 4K1, Canada and ∥Institut de Génétique Humaine, CNRS, 141 Rue de la Cardonille, 34396 Montpellier Cedex 5, France
- ‡‡ To whom correspondence should be addressed: Dept. of Biology, McMaster University, 1280 Main St. West, Hamilton, Ontario L8S 4K1, Canada. Tel.: 905-525-9140 (ext. 2-4833); Fax: 905-522-6066; E-mail: camposa{at}mcmaster.ca.
Abstract
We report the identification of the Disco Interacting Protein 1 (DIP1) gene isolated in a yeast interaction trap screen using the zinc finger protein disconnected (disco) as a bait. DIP1 encodes a protein containing two double-stranded RNA binding domains (dsRBD). Consistent with the presence of dsRBD, DIP1 binds dsRNA or structured RNAs in Northwestern assays. DIP1 is found in nuclear subdomains resembling speckles known to accumulate transcription and splicing factors. In early embryos, nuclear localization of DIP1 protein coincides with the onset of zygotic gene expression. Later in development DIP1 expression is decreased in dividing cells in different tissues. Overexpression of DIP1 in the eye-antennal imaginal disc, early in embryonic and larval development, causes the formation of supernumerary structures in the head capsule. A role for DIP1 in epigenetic mechanisms that lead to the establishment and/or maintenance of cell fate specification is discussed.
Footnotes
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↵1 The abbreviations used are: dsRNA, double-stranded RNA; DIP1, Disco interacting protein 1; dsRBD, double-stranded RNA binding domain; DSRBP, dsRNA-binding proteins; disco, disconnected; Ubx, Ultrabithorax; ey, eyeless; hth, homothorax; salm, spalt major; dll, distalless; NLS, nuclear localization signal; UTR, untranslated region; RED1, glutamate receptor RNA editase; ADAR1, human RNA-editing enzyme; GST, glutathione S-transferase; X-gal, 5-bromo-4-chloro-3-indolyl-β-galactopyranoside.
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↵* This work was supported by a Natural Sciences and Engineering Research Council Grant (to A. R. C.), by CNRS, and Association pour la Recherche sur le Cancer grants (to A. P. and A. B.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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The on-line version of this article (available at http://www.jbc.org) contains Fig. 12 and 13.
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↵§ Present address: Laboratory of Mammalian Genes and Development, National Institutes of Health, Bethesda, MD 20892.
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↵¶ Present address: Dept. of Biochemistry, McMaster University, 1280 Main St. West, Hamilton, Ontario L8S 4K1, Canada.
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↵** Present address: Hubrecht Lab, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
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- Received April 4, 2003.
- Revision received June 18, 2003.
- The American Society for Biochemistry and Molecular Biology, Inc.
