Factor inhibiting HIF (FIH) negatively regulates antiviral innate immunity via hydroxylation of IKKɛ
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo Sapiens
SUBMITTER: 
Wuhan Xiao
PROVIDER: PXD047193 | iProX | Thu Nov 23 00:00:00 GMT 2023
REPOSITORIES: iProX
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Project description:The aspariginyl-hydroxylase activity of Factor Inhibiting HIF (FIH) is a key regulator of the transcriptional activity of the hypoxia inducible factor. FIH also catalyses the hydroxylation of asparaginyl- and other-residues in ankyrin repeat domain (ARD) containing proteins, including Apoptosis stimulating of p53 (ASPP) protein family members. ASPP2 is reported to undergo a single FIH catalysed hydroxylation at Asn-986. We report biochemical and crystallographic evidence showing FIH can catalyse the unprecedented post-translational hydroxylation of both asparaginyl-residues in “VNVN” and related motifs of ankyrin repeat domains in apoptosis-stimulating of p53 (ASPP) proteins (i.e. ASPP1, ASPP2 and iASPP) and the related ASB11 and p18-INK4C proteins. The results extend the substrate scope of FIH catalysis and may have implications for its role in the hypoxic response and, ASPP protein function.
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Project description:Factor-inhibiting HIF (FIH) is an asparagine hydroxylase that acts on hypoxia-inducible factors (HIFs) to control cellular adaptation to hypoxia. FIH is expressed in several tumor types, but its impact in tumor progression remains largely unexplored. We observed that FIH was expressed on human lung cancer tissue. Deletion of FIH in mouse and human lung cancer cells resulted in an increased glycolytic metabolism, consistent with increased HIF activity. FIH-deficient lung cancer cells exhibited decreased proliferation. Analysis of RNA-Seq data confirmed changes in the cell cycle and survival and revealed molecular pathways that were dysregulated in the absence of FIH, including the upregulation of angiomotin (Amot), a key component of the Hippo tumor suppressor pathway. We show that FIH-deficient tumors were characterized by higher immune infiltration of NK and T cells compared with FIH competent tumor cells. In vivo studies demonstrate that FIH deletion resulted in reduced tumor growth and metastatic capacity. Moreover, high FIH expression correlated with poor overall survival in non-small cell lung cancer (NSCLC). Our data unravel FIH as a therapeutic target for the treatment of lung cancer.
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