Targeted proteolysis of the histone H3 tail facilitates epigentic reporgramming during differentiation

Though limited proteolysis of the histone H3 N-terminal tail (H3NT) is frequently observed during mammalian differentiation, however the specific genomic sites targeted for H3NT proteolysis and their functional significance of H3NT cleavage remain unknown.We used genome wide RNA-seq approaches to an established cell model of osteoclast differentiation. We discovered that H3NT proteolysis is selectively targeted near transcription start sites of a small group of genes and that most of these H3NT-cleaved genes are epigenetically regulated during osteoclastogenesis.We have identified that the principal H3NT protease of osteoclastogenesis is matrix metalloproteinase 9 (MMP-9). We next studied genomewide mRNA expression in MMP9 knockout cells and its effect in the epigenetic reprogramming of gene pathways required for proficient osteoclastogenesis. Overall design: Differential expresssion profile of transcripts in wt and MMP9 knockout cells

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Kim K, Punj V, Kim JM, Lee S, Ulmer TS, Lu W, Rice JC, An W