Project description:HOXB13 is a homeodomain transcription factor with prostate-specific expression. It is essential for normal prostate epithelium differentiation during development and functions as a key regulator of androgen-dependent cell growth in adult and cancerous prostate. Previous studies have demonstrated that HOXB13 is a pioneer factor of the androgen receptor (AR) and also a critical cofactor of AR variant v7 in castration-resistant prostate cancer (PCa). However, the intrinsic function of HOXB13 as a DNA-binding protein in an AR-independent context has not been elucidated. Here, our data reveal HOXB13, but not G84E mutant, recruits HDAC3 to specific genomic regions to catalyze histone de-acetylation and chromatin remodeling. We demonstrate a predominant function of HOXB13 in transcriptional repression of lipogenic genes requiring HDAC3.
Project description:HOXB13 is a homeodomain transcription factor with prostate-specific expression. It is essential for normal prostate epithelium differentiation during development and functions as a key regulator of androgen-dependent cell growth in adult and cancerous prostate. Previous studies have demonstrated that HOXB13 is a pioneer factor of the androgen receptor (AR) and also a critical cofactor of AR variant v7 in castration-resistant prostate cancer (PCa). However, the intrinsic function of HOXB13 as a DNA-binding protein in an AR-independent context has not been elucidated. Here, our data reveal HOXB13, but not G84E mutant, recruits HDAC3 to specific genomic regions to catalyze histone de-acetylation and chromatin remodeling. We demonstrate a predominant function of HOXB13 in transcriptional repression of lipogenic genes requiring HDAC3.
Project description:Liver-specific depletion of HDAC3 leads to liver steatosis (fatty liver), suggesting disregulation of lipid metabolism. This is correlated with changes in lipid metabolic gene expression. Livers depleted of HDAC3 were removed from 12 week old male HDAC3 fl/fl mice (loxP sites flanking exon 4 to 7 of the HDAC3 gene encoding the catalytic domain of HDAC3) one week after the injection of AAV2/8-Tbg-Cre virus. Livers from the HDAC3 fl/fl mice injected with AAV2/8-Tbg-GFP were used as normal controls. mRNA was extracted from 100mg mouse liver samples and hybridized to Affymetrix microarrays. For each group (HDAC3 depleted liver and normal liver), we have 5 samples from different mice.
Project description:To identify potential cofactors of HOXB13 in suppressing lipogenic programs in prostate cancer cells, we performed tandem affinity purification followed by mass spectrometry analysis of WT and G84E HOXB13 expressed in LNCaP cells. Out of the HOXB13-enriched proteins are previously reported interactors such as AR and its cofactors FOXA1, GATA2, and NKX3. However, these interactions were not disrupted by G84E as compared to WT HOXB13. Interestingly, we found strong interactions of HOXB13 with HDAC1/3 and their corepressors NCoR1/2 and TBL1X. Notably, these interactions were drastically reduced by G84E mutation.
Project description:Liver-specific depletion of HDAC3 leads to liver steatosis (fatty liver), suggesting disregulation of lipid metabolism. This is correlated with changes in lipid metabolic gene expression. Livers depleted of HDAC3 were removed from 12 week old male HDAC3 fl/fl mice (loxP sites flanking exon 4 to 7 of the HDAC3 gene encoding the catalytic domain of HDAC3) one week after the injection of AAV2/8-Tbg-Cre virus. Livers from the HDAC3 fl/fl mice injected with AAV2/8-Tbg-GFP were used as normal controls.
Project description:We address the function of HDAC3 in skeletal muscle metabolism We performed HDAC3 ChIP-seq, RNA-seq, and GRO-seq in mouse muscles at different times of the day and compared between WT and HDAC3-depleted muscles.
Project description:The histone deacetylase HDAC3 is a critical mediator of hepatic lipid metabolism, and liver-specific deletion of HDAC3 leads to fatty liver. To elucidate the underlying mechanism we developed a method of cross-linking followed by mass spectrometry to define a high-confidence HDAC3 interactome in vivo that includes the canonical NCoR/HDAC3 complex as well as Prospero-related homeobox 1 protein (PROX1). HDAC3 and PROX1 co-localize extensively on the mouse liver genome, and are co-recruited by Hepatocyte Nuclear Factor 4α (HNF4α). The HDAC3-PROX1 module controls the expression of a gene program regulating lipid homeostasis, and hepatic-specific ablation of either component increases triglyceride content in liver. These findings underscore the importance of specific combinations of transcription factors and coregulators in the fine tuning of organismal metabolism.