title: High mobility group proteins HMGD and HMGZ interact genetically with the Brahma chromatin remodeling complex in Drosophila.
abstract: Many pleiotropic roles have been ascribed to small abundant HMG-Box (HMGB) proteins in higher eukaryotes but their precise function has remained enigmatic. To investigate their function genetically we have generated a defined deficiency uncovering the functionally redundant genes encoding HMGD and HMGZ, the Drosophila counterparts of HMGB1-3 in mammals. The resulting mutant is a strong hypomorphic allele of HmgD/Z. Surprisingly this allele is viable and exhibits only minor morphological defects even when homozygous. However, this allele interacts strongly with mutants of the Brahma chromatin remodeling complex, while no interaction was observed with mutant alleles of other remodeling complexes. We also observe genetic interactions between the HmgD/Z deficiency and some, but not all, known Brahma targets. These include the homeotic genes Sex combs reduced and Antennapedia, as well as the gene encoding the cell-signaling protein Rhomboid. In contrast to more general structural roles previously suggested for these proteins, we infer that a major function of the abundant HMGB proteins in Drosophila is to participate in Brahma-dependent chromatin remodeling at a specific subset of Brahma-dependent promoters.
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge CB2 2QH, United Kingdom. a.ragab@dkfz-heidelberg.de
authors.forename: Anan
authors.initials: A
authors.lastname: Ragab
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Thompson
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Travers
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly / Q000235:genetics*; D029721:Drosophila Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014921:Wings, Animal / Q000033:anatomy & histology
chemical_list: D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; C511073:HMGZ protein, Drosophila; D006609:High Mobility Group Proteins; C106685:HmgD protein, Drosophila; D008565:Membrane Proteins; C081481:Rho protein, Drosophila; D015534:Trans-Activators; C086469:brm protein, Drosophila