In A. nidulans CCAAT sequences are found upstream of a number of genes and are recognised by AnCF, a complex consisting of three evolutionary conserved subunits HapB,HapC,Hap E (1). Many eukaryotic promoters are assembled into chromatin structures hypersensitive to DNase I prior to transcriptional activation. We have found that the Hap-complex is involved in the formation of a DNase I hypersensitive region in the promoter of the amdS gene in A. nidulans In a hapE deletion strain no DNase I hypersensitive site is formed. Likewise, a point mutation in the CCAAT motif as well as a 530 by deletion which removes most of the regulatory motifs of the amdS promoter including the CCAAT box results in complete loss of the DNase I hypersensitive region. This DNase I hypersensitive region can be restored by insertion of a 30 by oligonucleotide carrying the CCAAT motif. DNase I hypersensitive regions have been found in the CCAAT containing promoters of the niiA, fmdS and gdhA genes and were also hapE -dependent. In all 4 promoters CCAAT boxes are located within the DNase I hypersensitive region. These data imply a critical role for the AnCF complex in establishing DNase I sensitive regions in A. nidulans. Recently a role for the NF-Y complex in chromatin rearrangement in vertebrates has also been proposed (2,3). This work was supported by the Austrian Science Foundation (J 1518-GEN) and the Australian Research Council. 1. Steidl, S., Papagiannopoulos, P., Litzka, O., Andrianopoulos A., Davis, M.A., Brakhge, A.A. and Hynes, M.J. Mol. Cell Biol. in press 2. Jin, S. and Scotto, K.W. (1998) Mol. Cell Biol. 18: 4377-4383. 3. Li, Q., Herder, M., Landsberger, N., Kaludov, N., Ogryzko, V.V., Nakatani, Y. and Wolffe A.P. (1998) EMBOJ. 17:6300-6315.
Fungal Genet. Newsl. 46 (Supl):
Full conference title:
Fungal Genetics Conference 20th
- Fungal Genetics Conference 20th (1999)