Americo et al., 2002, Genetics 160(4): 1561--1571

Americo et al., 2002, Genetics 160(4): 1561--1571
FlyBase Identifier	FBrf0147066
FlyBase URL	http://flybase.org/reports/FBrf0147066.html
Publication Type	paper
Publication Year	2002
PubMed ID	11973310
PubMed URL	http://www.ncbi.nlm.nih.gov/pubmed/11973310

Title

A complex array of DNA-binding proteins required for pairing-sensitive silencing by a Polycomb group response element From the Drosophila engrailed gene.

Abstract

Regulatory DNA from the Drosophila gene engrailed causes silencing of a linked reporter gene (mini-white) in transgenic Drosophila. This silencing is strengthened in flies homozygous for the transgene and has been called "pairing-sensitive silencing." The pairing-sensitive silencing activities of a large fragment (2.6 kb) and a small subfragment (181 bp) were explored. Since pairing-sensitive silencing is often associated with Polycomb group response elements (PREs), we tested the activities of each of these engrailed fragments in a construct designed to detect PRE activity in embryos. Both fragments were found to behave as PREs in a bxd-Ubx-lacZ reporter construct, while the larger fragment showed additional silencing capabilities. Using the mini-white reporter gene, a 139-bp minimal pairing-sensitive element (PSE) was defined. DNA mobility-shift assays using Drosophila nuclear extracts suggested that there are eight protein-binding sites within this 139-bp element. Mutational analysis showed that at least five of these sites are important for pairing-sensitive silencing. One of the required sites is for the Polycomb group protein Pleiohomeotic and another is GAGAG, a sequence bound by the proteins GAGA factor and Pipsqueak. The identity of the other proteins is unknown. These data suggest a surprising degree of complexity in the DNA-binding proteins required for PSE function.

Genes from Reference

Gene(s)	Dmel\w