The complexity in composition and function of the eukaryotic nucleus is achieved 
through its organization in specialized nuclear compartments. The Drosophila 
chromatin remodeling ATPase ISWI plays evolutionarily conserved roles in 
chromatin organization. Interestingly, ISWI genetically interacts with the hsrω 
gene, encoding multiple non-coding RNAs (ncRNA) essential, among other 
functions, for the assembly and organization of the omega speckles. The 
nucleoplasmic omega speckles play important functions in RNA metabolism, in 
normal and stressed cells, by regulating availability of hnRNPs and some other 
RNA processing proteins. Chromatin remodelers, as well as nuclear speckles and 
their associated ncRNAs, are emerging as important components of gene regulatory 
networks, although their functional connections have remained poorly defined. 
Here we provide multiple lines of evidence showing that the hsrω ncRNA interacts 
in vivo and in vitro with ISWI, regulating its ATPase activity. Remarkably, we 
found that the organization of nucleoplasmic omega speckles depends on ISWI 
function. Our findings highlight a novel role for chromatin remodelers in 
organization of nucleoplasmic compartments, providing the first example of 
interaction between an ATP-dependent chromatin remodeler and a large ncRNA.