Drosophila, homeobox, brahma, homeotic, transcription, chromatin, hedgehog
Regulation of the homeotic genes of the Antennapedia and bithorax complexes in Drosophila requires multiple cis-acting DNA sequences. Many of these cis-acting elements are redundant and are located up to 100kb from the promoter. By screening for mutations that fail to properly regulate the homeotic genes, the lab has identified eighteen new trans-acting factors required for the function of these cis-acting regulatory elements. One of the new trans-acting factors, the brahma protein, is related to yeast and mammalian transcription factors that form part of a protein complex that facilitates transcription by altering chromatin structure. Trans-acting factors required for function of the hedgehog gene have also been identified. Many of these are the same factors required for function of the homeotic genes. Current work is directed towards identifying factors that interact with the brahma complex, including the TBP-associated factors (TAFs) and homeotic cis-regulatory elements as well as the molecular characterization of other new trans-acting factors already identified.
Kennison JA, (1995) The Polycomb and trithorax group proteins of Drosophila: Trans- regulators of homeotic gene function, Annu.Rev.Genet. 29:289-303.
Felsenfeld AL and Kennison JA, (1995) Positional signaling by hedgehog in Drosophila imaginal disc development, Development 121:1-10.
Brizuela BJ, Elfring L, Ballard J, Tamkun JW, and Kennison JA, (1994) Genetic analysis of the brahma gene of Drosophila melanogaster and polytene chromosome subdivisions 72AB, Genetics 137:803-813.
Kennison JA, (1993) Transcriptional activation of Drosophila homeotic genes from distant regulatory elements, Trends in Genetics 9:75-79.
Tamkun JW et al. (1992) brahma: a regulator of Drosophila homeotic genes structurally related to the yeast transcriptional activator SNF2/SWI2, Cell 68:561-572.