SETD1A regulates transcriptional pause release of heme biosynthesis genes in leukemia [RNA-seq]

Histone methyltransferase SETD1A is critical for acute myeloid leukemia (AML) cell survival, but the molecular mechanism driving SETD1A gene regulation remains elusive. To delineate the role of SETD1A, we utilize a protein degrader technology to induce rapid SETD1A degradation in AML cell lines. SETD1A degradation results in immediate downregulation of transcripts associated with DNA repair and heme biosynthesis pathways. CRISPR-based functional analyses and metabolomics revealed an essential role of SETD1A to maintain mitochondrial respiration in AML cells. These SETD1A targets are enriched in head-to-head (H2H) genes. SETD1A degradation disturbs a non-enzymatic SETD1A domain-dependent cyclin K function, increases the mono-Ser5P RNA polymerase II (RNAP2) at TSS, and induces the promoter-proximal pausing of RNAP2 in a strand-specific manner. This study reveals a non-enzymatic role for SETD1A in transcriptional pause release and provides insight into the mechanism of RNAP2 pausing and its function in cancer. Overall design: 1) Examination of SETD1A targets in human MOLM-13 leukemia cell line, 2) Examination of histone modifications and RNAP2 modifications in SETD1A degraded MOLM-13 leukemia cell line. 3) Examination of elongation regulators in SETD1A degraded MOLM-13 leukemia cell line