Immunoprecipitated proteins on beads were washed once and resuspended in 50 mM ammonium bicarbonate, followed by the addition of 200 ng trypsin/Lys-C mix and an overnight incubation at 37ºC. The digests were reduced, alkylated, acidified, and desalted with GL-Tip SDB. Then, the eluates were evaporated and dissolved in 0.1% trifluoroacetic acid and 3% acetonitrile (ACN). LC-MS/MS analysis of the resultant peptides was performed on an EASY-nLC 1200 UHPLC connected to an Orbitrap Fusion mass spectrometer through a nanoelectrospray ion source (Thermo Fisher Scientific). The peptides were separated on a 75-µm inner diameter × 150 mm C18 reversed-phase column (Nikkyo Technos) with a linear 4-32% ACN gradient for 0-100 min followed by an increase to 80% ACN for 10 min and finally held at 80% ACN for 10 min. The mass spectrometers were operated in data-dependent acquisition mode. Raw data were directly analyzed against the UniProt database restricted to Drosophila melanogaster using Proteome Discoverer 2.5 (Thermo Fisher Scientific) with the Sequest HT search engine. Peptides were filtered at a false discovery rate of 1% using the Percolator node. Label-free quantification was performed based on intensities of precursor ions using the Precursor Ions Quantifier node. Normalization was performed such that the total sum of abundance values for each sample over all peptides was the same.