Role of CtBP in transcriptional repression by the Drosophila giant protein.

The giant protein is a short-range transcriptional repressor that refines the expression pattern of gap and pair-rule genes in the Drosophila blastoderm embryo. Short-range repressors including knirps, Krüppel, and snail utilize the CtBP cofactor for repression, but it is not known whether a functional interaction with CtBP is a general property of all short-range repressors. We studied giant repression activity in a CtBP mutant and find that this cofactor is required for giant repression of some, but not all, genes. While targets of giant such as the even-skipped stripe 2 enhancer and a synthetic lacZ reporter show clear derepression in the CtBP mutant, another giant target, the hunchback gene, is expressed normally. A more complex situation is seen with regulation of the Krüppel gene, in which one enhancer is repressed by giant in a CtBP-dependent manner, while another is repressed in a CtBP-independent manner. These results demonstrate that giant can repress both via CtBP-dependent and CtBP-independent pathways, and that promoter context is critical for determining giant-CtBP functional interaction. To initiate mechanistic studies of the giant repression activity, we have identified a minimal repression domain within giant that encompasses residues 89-205, including an evolutionarily conserved region bearing a putative CtBP binding motif.

[1]  V. Pirrotta,et al.  The giant gene of Drosophila encodes a b-ZIP DNA-binding protein that regulates the expression of other segmentation gap genes. , 1992, Development.

[2]  A. Courey,et al.  Groucho/TLE family proteins and transcriptional repression. , 2000, Gene.

[3]  S. Parkhurst,et al.  Drosophila CtBP: a Hairy‐interacting protein required for embryonic segmentation and Hairy‐mediated transcriptional repression , 1998, The EMBO journal.

[4]  H. Jäckle,et al.  Gene expression mediated by cis‐acting sequences of the Krüppel gene in response to the Drosophila morphogens bicoid and hunchback. , 1991, The EMBO journal.

[5]  M. Levine,et al.  Interaction of short-range repressors with Drosophila CtBP in the embryo. , 1998, Science.

[6]  N. Patel,et al.  Evidence for stabilizing selection in a eukaryotic enhancer element , 2000, Nature.

[7]  N. Perrimon,et al.  The autosomal FLP-DFS technique for generating germline mosaics in Drosophila melanogaster. , 1996, Genetics.

[8]  M. Levine,et al.  Spacing ensures autonomous expression of different stripe enhancers in the even-skipped promoter. , 1993, Development.

[9]  S. Sather,et al.  Analysis of Krüppel control elements reveals that localized expression results from the interaction of multiple subelements. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[10]  A. Grinberg,et al.  DNA sequence‐dependent folding determines the divergence in binding specificities between Maf and other bZIP proteins , 2001, The EMBO journal.

[11]  E. Davidson,et al.  The hardwiring of development: organization and function of genomic regulatory systems. , 1997, Development.

[12]  M. Levine,et al.  Mutually repressive interactions between the gap genes giant and Krüppel define middle body regions of the Drosophila embryo. , 1991, Development.

[13]  M. Levine,et al.  Short-range repression permits multiple enhancers to function autonomously within a complex promoter. , 1994, Genes & development.

[14]  M. Levine,et al.  Regulation of a segmentation stripe by overlapping activators and repressors in the Drosophila embryo. , 1991, Science.

[15]  D. Maier,et al.  Rapid divergence in the course of Drosophila evolution reveals structural important domains of the Notch antagonist Hairless , 1999, Development Genes and Evolution.

[16]  N. Patel,et al.  Functional analysis of eve stripe 2 enhancer evolution in Drosophila: rules governing conservation and change. , 1998, Development.

[17]  Q. Zhang,et al.  Acetylation of adenovirus E1A regulates binding of the transcriptional corepressor CtBP. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[18]  Z. Paroush,et al.  Groucho acts as a corepressor for a subset of negative regulators, including Hairy and Engrailed. , 1997, Genes & development.

[19]  M. Levine,et al.  Long-range repression in the Drosophila embryo. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[20]  S. Small,et al.  Two distinct mechanisms for differential positioning of gene expression borders involving the Drosophila gap protein giant. , 1998, Development.

[21]  M. Levine,et al.  Groucho and dCtBP mediate separate pathways of transcriptional repression in the Drosophila embryo. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[22]  M Hoch,et al.  cis‐acting control elements for Krüppel expression in the Drosophila embryo. , 1990, The EMBO journal.

[23]  M. Levine,et al.  The eve stripe 2 enhancer employs multiple modes of transcriptional synergy. , 1996, Development.

[24]  M. Levine,et al.  dCtBP mediates transcriptional repression by Knirps, Krüppel and Snail in the Drosophila embryo , 1998, The EMBO journal.

[25]  M. Levine,et al.  Regulation of even‐skipped stripe 2 in the Drosophila embryo. , 1992, The EMBO journal.

[26]  M Hoch,et al.  Competition for overlapping sites in the regulatory region of the Drosophila gene Krüppel. , 1992, Science.

[27]  David N. Arnosti,et al.  dCtBP-Dependent and -Independent Repression Activities of the Drosophila Knirps Protein , 2000, Molecular and Cellular Biology.

[28]  G. Chinnadurai,et al.  Structural Determinants Present in the C-terminal Binding Protein Binding Site of Adenovirus Early Region 1A Proteins* , 1998, The Journal of Biological Chemistry.

[29]  S. Carroll,et al.  The zygotic control of Drosophila pair-rule gene expression. I. A search for new pair-rule regulatory loci. , 1989, Development.

[30]  A. Wilson,et al.  Molecular Evolution in Drosophila and the Higher Diptera II. A Time Scale for Fly Evolution , 1984 .

[31]  J. Burr,et al.  Functional analysis of repressor binding sites in the iab-2 regulatory region of the abdominal-A homeotic gene. , 2000, Developmental biology.

[32]  Arjumand Ghazi,et al.  Developmental biology: Control by combinatorial codes , 2000, Nature.

[33]  J. Reinitz,et al.  Transcriptional repression by the Drosophila giant protein: cis element positioning provides an alternative means of interpreting an effector gradient. , 1999, Development.

[34]  C. Osborne,et al.  Binding of CtIP to the BRCT Repeats of BRCA1 Involved in the Transcription Regulation of p21 Is Disrupted Upon DNA Damage* , 1999, The Journal of Biological Chemistry.

[35]  M. Levine,et al.  CtBP-dependent activities of the short-range Giant repressor in the Drosophila embryo , 2001, Proceedings of the National Academy of Sciences of the United States of America.