Heterochromatin is enriched for specific epigenetic factors including Heterochromatin Protein 1a (HP1a), and is essential for many organismal functions. To elucidate heterochromatin organization and regulation, we purified Drosophila melanogaster HP1a interactors, and performed a genome-wide RNAi screen to identify genes that impact HP1a levels or localization. The majority of the over four hundred putative HP1a interactors and regulators identified were previously unknown. We found that 13 of 16 tested candidates (83%) are required for gene silencing, providing a substantial increase in the number of identified components that impact heterochromatin properties. Surprisingly, image analysis revealed that although some HP1a interactors and regulators are broadly distributed within the heterochromatin domain, most localize to discrete subdomains that display dynamic localization patterns during the cell cycle. We conclude that heterochromatin composition and architecture is more spatially complex and dynamic than previously suggested, and propose that a network of subdomains regulates diverse heterochromatin functions.
Genome-wide screen
FlyRNAi.org--the database of the Drosophila RNAi screening center: 2012 update.” Nucleic Acids Res, 40, Database issue, Pp. D715-9.Abstract
. 2012. “
Functional genomic analysis of the Wnt-wingless signaling pathway.” Science, 308, 5723, Pp. 826-33.Abstract
. 2005. “
Design and implementation of high-throughput RNAi screens in cultured Drosophila cells.” Nat Protoc, 2, 9, Pp. 2245-64.Abstract
. 2007. “
Genome-wide RNAi screen identifies Letm1 as a mitochondrial Ca2+/H+ antiporter.” Science, 326, 5949, Pp. 144-7.Abstract
. 2009. “
Identification of chromatin-associated regulators of MSL complex targeting in Drosophila dosage compensation.” PLoS Genet, 8, 7, Pp. e1002830.Abstract
. 2012. “
CRACM1 is a plasma membrane protein essential for store-operated Ca2+ entry.” Science, 312, 5777, Pp. 1220-3.Abstract
. 2006. “
Comparative analysis of argonaute-dependent small RNA pathways in Drosophila.” Mol Cell, 32, 4, Pp. 592-9.Abstract
. 2008. “
A genome-wide RNAi screen identifies core components of the G₂-M DNA damage checkpoint.” Sci Signal, 4, 154, Pp. rs1.Abstract
. 2011. “
A functional insulator screen identifies NURF and dREAM components to be required for enhancer-blocking.” PLoS One, 9, 9, Pp. e107765.Abstract
. 2014. “
Drosophila RNAi screen reveals CD36 family member required for mycobacterial infection.” Science, 309, 5738, Pp. 1251-3.Abstract
. 2005. “
A genome-wide RNAi screen reveals multiple regulators of caspase activation.” J Cell Biol, 179, 4, Pp. 619-26.Abstract
. 2007. “
A genomewide RNA interference screen for modifiers of aggregates formation by mutant Huntingtin in Drosophila.” Genetics, 184, 4, Pp. 1165-79.Abstract
. 2010. “
A genome-wide RNA interference screen identifies new regulators of androgen receptor function in prostate cancer cells.” Genome Res, 23, 4, Pp. 581-91.Abstract
. 2013. “
A functional genomic analysis of cell morphology using RNA interference.” J Biol, 2, 4, Pp. 27.Abstract
. 2003. “