TY - JOUR T1 - Post-translational modifications of <em>Drosophila melanogaster</em> HOX protein, Sex combs reduced JF - bioRxiv DO - 10.1101/512962 SP - 512962 AU - Anirban Banerjee AU - Anthony Percival-Smith Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/01/08/512962.abstract N2 - Homeotic selector (HOX) transcription factors (TFs) regulate gene expression that determines the identity of Drosophila body segments along the anterior-posterior (A-P) axis. Besides a highly conserved DNA-binding homeodomain (HD), HOX proteins also contain functionally important, evolutionarily conserved small motifs, which may be Short Linear Motifs (SLiMs). SLiMs are proposed to be sites of phosphorylation and this may regulate the activity of HOX proteins. Sex combs reduced protein fused to a triple tag (SCRTT) was extracted from developing embryos that express SCRTT from a heat-shock promoter fusion gene and purified using Ni-NTA beads under denaturing conditions. Multiple sites of post-translational modification (PTM) were identified in purified SCRTT by Tandem Mass Spectrometry (MS/MS). The identified PTMs include phosphorylation at S185, S201, T315, S316, T317 and T324, acetylation at K218, S223, S227, K309, K434 and K439, formylation at K218, K309, K325, K341, K369, K434 and K439, methylation at S19, S166, K168 and T364, carboxylation at D108, K298, W307, K309, E323, K325 and K369, and hydroxylation at P22, Y87, P107, D108, D111, P269, P306, R310, N321, K325, Y334, R366, P392 and Y398. We found no support for the hypothesis that predicted SLiMs in SCR are preferential sites of phosphorylation.AbbreviationsA-Panterior-posteriorHOXhomeotic selectorSCRSex combs reducedTTtriple tagPBProboscipediaHDhomeodomainPTMpost-translational modificationTFtranscription factorHAThistone acetyltransferaseHDAChistone deacetylaseMSmass spectrometrySLiMshort linear motifAELafter egg layingADaverage depthADorcaverage depth of regions coveredCIDCollision-Induced DissociationCTDC-terminal domainESIElectrospray ionizationFDRfalse discovery rateLCliquid chromatography ER -