Products of the grg (Groucho-related Gene) Family Can Dimerize through the Amino-terminal Q Domain*
- From the Molecular Biology Institute, Cancer Research Group and Departments of Biochemistry and Medical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
- ↵‡To whom correspondence should be addressed: Molecular Biology Institute, LSB 425, McMaster University, 1280 Main St. W., Hamilton, Ontario L8S 4K1, Canada. Tel.: 905-525-9140, ext. 27335; Fax: 905-521-2955.
Abstract
The murine grg (Groucho-related gene) products are believed to interact with transcription factors and repress transcription, thereby regulating cell proliferation and differentiation. Most proteins in the grg family contain all of the domains found in the Drosophila Groucho protein, including the S/P (Ser-Pro-rich) domain required for interaction with transcription factors and the WD40 domain, which is thought to interact with other proteins. However, at least two Grg proteins contain only the amino-terminal Q (glutamine-rich) domain. We examined whether the Q domain is used for dimerization between Grg proteins, using the yeast two-hybrid system and binding assays with glutathione S-transferase fusion proteins. We found that Grg proteins are able to dimerize through the Q domain and that dimerization requires a core of 50 amino acids. Surprisingly, the dimerization does not require the leucine zipper located within the Q domain.
Footnotes
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↵§ Scholar of the Medical Research Council of Canada.
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↵* This work was supported by a grant from the Medical Research Council of Canada. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
- Received August 9, 1996.
- © 1996 by The American Society for Biochemistry and Molecular Biology, Inc.
