HIF-1 Interacts with TRIM28 and DNA-PK to release paused RNA polymerase II and activate target gene transcription in response to hypoxia.

ABSTRACT: Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that acts as a regulator of oxygen (O₂) homeostasis in metazoan species by binding to hypoxia response elements (HREs) and activating the transcription of hundreds of genes in response to reduced O₂ availability. RNA polymerase II (Pol II) initiates transcription of many HIF target genes under non-hypoxic conditions but pauses after approximately 30-60 nucleotides and requires HIF-1 binding for release. Here we report that in hypoxic breast cancer cells, HIF-1 recruits TRIM28 and DNA-dependent protein kinase (DNA-PK) to HREs to release paused Pol II. We show that HIF-1α and TRIM28 assemble the catalytically-active DNA-PK heterotrimer, which phosphorylates TRIM28 at serine-824, enabling recruitment of CDK9, w

SUBMITTER: Yang Y 

PROVIDER: S-EPMC8760265 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature