An endogenous Su(Hw) insulator separates theyellowgene from theAchaete-scutegene complex inDrosophila

Abstract

There was an error published in Development 130, 3249-3258.The name of the second author, Inna Biryukova, was published incorrectly. The name is correct as written above.The authors apologise to readers for this mistake.

An endogenous Suppressor of Hairy-wing insulator separates regulatory domains in Drosophila

“…4). Our findings suggest that enhancer blocking by 1A-2 is less dependent on the Su(Hw) protein than previously reported (39) and imply that the Su(Hw) protein cooperates with other protein(s) bound to 1A-2 to prevent enhancer-promoter communication.…”

“…Insertion of 1A-2 upstream of the yellow wing and body enhancers did not interfere with enhancer function (data not shown), demonstrating that 1A-2 effects on gene expression are position-dependent. The 1A-2 region was independently identified due to disruption of enhancer activated transcription in the achaete-scute gene cluster and subsequently shown to block the white eye enhancer (39). Taken together these data suggest that 1A-2 has general enhancer blocking effects.…”

“…Although it is possible that the distinct sequence of 1A-2 permits DNA association by the Su(Hw) f protein due to different zinc finger requirements for binding, we favor the alternative that other proteins are needed for the residual block. Interestingly, a 125-bp fragment of 1A-2 that includes only the Su(Hw)-binding sites does not confer enhancer blocking (39), demonstrating that the 1A-2 Su(Hw) sites are not sufficient for insulator activity. The identity of the putative insulator protein is unknown, as 1A-2 does not contain binding sites for the known Drosophila insulator proteins, Zw5, BEAF, or GAGA factor (40)(41)(42).…”

Functional Requirements for Fab-7 Boundary Activity in the Bithorax Complex

“…To explore this possibility, we used antibodies directed against known insulator proteins for supershift experiments. The antibodies tested included BEAF, CP190, Elba, Enhancer of yellow 2 [E(y)2], Insensitive (Insv), Lola-like, Mod(mdg4), Su(Hw), and Pita (11,14,24,33,35,57,(72)(73)(74)(75)(76)(77)(78)(79)(80)(81)(82). Like GAF (and Pipsqueak), CP190 and Lola-like have N-terminal BTB protein-protein interaction domains and several C-terminal zinc fingers that mediate DNA binding.…”

“…The most thoroughly characterized Drosophila insulator is from the gypsy transposon and consists of reiterated sites for a single DNA binding protein (31,32). In contrast, endogenous fly insulators are generated by a unique assemblage of proteins on heterogeneous and rather large (Ͼ250 bp) sequences (33)(34)(35)(36)(37)(38)(39)(40). Moreover, in the few examples that have been studied in detail, this assemblage is a composite of functionally redundant cis/trans elements, with no single element being absolutely essential (3,(37)(38)(39)(40)(41).…”