Project description:PHD-finger protein 5A (PHF5A) is a component of U2snRNP, which plays a critical role in mRNA splicing for recognizing the branch site. However, whether it also plays other functions independent of RNA splicing remains elusive. Here, we find that expression levels of PHF5A are significantly upregulated in hepatocellular carcinoma (HCC). Down-regulation of PHF5A restrains liver cancer cell proliferation in vitro and in vivo. RNA-sequencing analysis reveals that fatty-acid biosynthetic enzymes are major downstream targets of PHF5A in HCC. Through metabolomics analysis, we find that inhibition of PHF5A reduces free fatty acid and phospholipid synthesis, further suppressing plasma membrane function. Mechanistically, PHF5A acts as a transcription co-factor of the p300 acetyltransferase for the H3K27 acetylation (Ac) and promotes H3K27Ac-dependent lipogenic genes expression. Our findings demonstrated a surprising splicing-independent role of PHF5A in transcriptional regulation of lipid metabolism for HCC progression and provided a new strategy for HCC therapy by blocking the interaction of PHF5A and p300.
Project description:The process utilized by cancer cells for adapting to cellular stress is a key point for carcinogenesis. Alternative pre-mRNA splicing induced post-transcriptional gene expression regulation is one of the pathways for tumors maintaining proliferation rates accompanying the malignant phenotype under stress. However, the protein post-translational modification, especially protein acetylation on pre-mRNA splicing processes under stress is unknown. Here, we uncovered a list of hyperacetylated proteins in the context of acutely reduced Acetyl-CoA levels under nutrient starvation. PHD finger-like domain-containing protein 5A (PHF5A/SF3b14b), a component of U2 snRNPs, can be acetylated at lysine 29 in response to multiple cellular stresses. P300 and HDAC6 regulate PHF5A acetylation levels. PHF5A acetylation strengthens the interaction among U2 snRNPs, and affects global pre-mRNA splicing pattern and extensive gene expression. PHF5A hyperacetylation induced alternative splicing stabilizes KDM3A mRNA and promotes its protein expression. Pathologically, PHF5A K29 hyperacetylation and KDM3A upregulation axis are correlated with poor prognosis of colon cancer patients. Our findings uncovered a novel mechanism of anti-stress pathway that acetylation on PHF5A promotes the cancer cells capacity for stress resistance and consequently contributes to colon carcinogenesis.
Project description:Phf5a regulates transcription elongation in mouse embryonic stem cells (ESCs), through regulation of the Paf1 complex. In this study we assayed for genome-wide localization of H2BK120-ub in mouse ESCs under conditions of shControl and shPhf5a knockdown. These results revealed that downregualtion of Phf5a results in the increase of the elongation mark H2BK120-ub from the gene bodies of pluripotency genes in ESC.
Project description:Phf5a regulates transcription elongation in mouse embryonic stem cells (ESCs), through regulation of the Paf1 complex. In this study we assayed nascent RNA profiling using global run-on sequncing in mouse ESCs under conditions of self-renewal, differentiation and Phf5a knockdown. These results revealed that genes positively regulated by Paf1 in ESCs exibit RNA elongation pausing on their promoters. We used conditions of self-renewal, differentiation, Phf5a knockdown and Paf1 knockdown to monitor nascent transcript expression changes during Phf5a depletion using global run-on RNA sequencing (GRO-seq). These results revealed that Phf5a through the control of Paf1 complex regulates pause release and elongation of pluripoency-associated genes in embryonic stem cells.
Project description:Phf5a regulates transcription elongation in mouse embryonic stem cells (ESCs), through regulation of the Paf1 complex. In this study we assayed for genome-wide localization of H3K4me3, H3K79me2 and H3K36me3 in mouse ESCs under conditions of shControl and shPhf5a knockdown. These results revealed that downregualtion of Phf5a results in the decrease of the elongation marks H3K79me2 and H3K36me3 from the gene bodies of pluripotency genes in ESC, wherease the promoter-associated mark H3K4me3 remains unaffected.
Project description:Transcription is regulated by a multitude of activators and repressors, which bind to the RNA polymerase II (Pol II) machinery and modulate its progression. Death-inducer obliterator (DIDO) and PHD finger protein 3 (PHF3) are paralogue proteins that regulate transcription elongation by docking onto phosphorylated serine-2 in the C-terminal domain (CTD) of Pol II through their SPOC domains. Here we show that DIDO3 and PHF3 form a complex that bridges the Pol II elongation machinery with chromatin and RNA processing factors, and tethers Pol II in a phase-separated microenvironment. Their SPOC domains and C-terminal intrinsically disordered regions are critical for transcription regulation. PHF3 and DIDO exert cooperative and antagonistic effects on the expression of neuronal genes and are both essential for neuronal differentiation. The dataset contains RNAseq of HEK293 cells with various perturbations of PHF3 and DIDO1 genes.
Project description:Several MYST-family histone acetyltransferase (HAT) enzymes associate with specific ING tumor suppressor proteins. ING complexes containing the HBO1 HAT protein are the major source of histone H4 acetylation in vivo and have been shown to play critical roles in gene regulation and DNA replication. Here, we present a molecular dissection of HBO1/ING HAT complexes that unravels the protein domains required for complex assembly and function. A distinctive characteristic of ING HAT complexes is the presence of multiple PHD finger domains in different subunits. Biochemical and functional analysis of these domains indicate that they interact with histone H3 N-terminal tail region but with different specificity towards the methylation status of lysine 4. They play essential and intricate role in regulating binding to chromatin and substrate specificity. This is achieved in part through expression of subunit isoforms controlling which PHD fingers are present in the complex. Importantly, localization analysis on the human genome indicate that HBO1 complexes are enriched throughout the coding region of genes, supporting a role in transcription elongation. These results also underline the importance and versatility of PHD finger domains in regulating chromatin association and trans-histone acetylation specificity within a single protein complex. ChIP-chip of FLAG-JADE1 +/- doxorubicin treatment in Hela cells
Project description:Phf5a regulates transcription elongation in mouse embryonic stem cells (ESCs), through regulation of the Paf1 complex. In this study we assayed for genome-wide localization of Ser-5-phosphorylated RNA polymerase II and Ser-2-phosphorylated RNA polymerase II in mouse ESCs under conditions of shControl and shPhf5a knockdown. These results revealed that downregualtion of Phf5a results in the increase of the initiating form of RNA polymerase II (Ser5-phosphorylated) and in the aberrant loss of the elongating form of RNA polymerase II (Ser2-phosphorylated) of pluripotency genes in ESCs.
Project description:Phf5a regulates transcription elongation in mouse embryonic stem cells (ESCs), through regulation of the Paf1 complex. In this study we assayed gene expression profiling using RNA-sequncing in mouse ESCs under conditions of self-renewal, Phf5a knockdown and Paf1 knockdown. These results revealed that Phf5a and Paf1 regulate similar gene expression signatures in mouse ESCs.