SETD2 methyltransferase activity aids gene definition by promoting correct transcription initiation and efficient pre-mRNA 3’ cleavage [RCC_3mRNAseq]

ABSTRACT: SETD2 is a key histone methyltransferase responsible for depositing histone H3 lysine 36 trimethylation (H3K36me3). Loss of its enzymatic activity has been implicated in various cancers, including renal cell carcinoma (RCC). In RCC, SETD2 mutations have been linked to defects in transcription termination, though the underlying mechanism remains unclear. Here, using nascent transcriptomics in SETD2 knockouts and RCC patient-derived cells, we show that SETD2 loss leads to delayed transcription termination, but only in a subset of genes. POINT-seq analysis reveals widespread transcriptional readthrough beyond canonical termination sites upon SETD2 loss/mutation, affecting 15–24% of genes. We demonstrate that defective termination following SETD2 loss/mutation is driven by a combination of increased cryptic transcription initiation and impaired 3′ pre-mRNA cleavage. In contrast, genes that maintain proper termination show significant downregulation. Additionally, we find that SETD2 ensures proper termination independently of alternative polyadenylation, underscoring the distinction between transcription termination and 3′ end processing. Our findings highlight that methyltransferase activity of SETD2 is a crucial regulator of transcriptional integrity, preventing cryptic initiation and promoting efficient 3′ end processing

ORGANISM(S): Homo sapiens

PROVIDER: GSE301035 | GEO | 2026/02/09

REPOSITORIES: GEO