PMID: 23084835 , Related PDB ids: 4B7Y, 4B86
Authors:
Hallacli E, Lipp M, Georgiev P, Spielman C, Cusack S, Akhtar A, Kadlec J
Title:
Msl1-mediated dimerization of the dosage compensation complex is essential for male X-chromosome regulation in Drosophila.
Journal:
Mol Cell. 2012 Nov 30;48(4):587-600. doi: 10.1016/j.molcel.2012.09.014. Epub 2012, Oct 18.
Abstract:
The Male-Specific Lethal (MSL) complex regulates dosage compensation of the male X chromosome in Drosophila. Here, we report the crystal structure of its MSL1/MSL2 core, where two MSL2 subunits bind to a dimer formed by two molecules of MSL1. Analysis of structure-based mutants revealed that MSL2 can only interact with the MSL1 dimer, but MSL1 dimerization is MSL2 independent. We show that Msl1 is a substrate for Msl2 E3 ubiquitin ligase activity. ChIP experiments revealed that Msl1 dimerization is essential for targeting and spreading of the MSL complex on X-linked genes; however, Msl1 binding to promoters of male and female cells is independent of the dimer status and other MSL proteins. Finally, we show that loss of Msl1 dimerization leads to male-specific lethality. We propose that Msl1-mediated dimerization of the entire MSL complex is required for Msl2 binding, X chromosome recognition, and spreading along the X chromosome.