Project description:This study was to find genes directly regulated by SND1 and VND7. SND1XVE- or VND7XVE-expressing cells were treated with cycloheximide alone (control) or with cycloheximide plus estradiol (experimental) to identify genes directly activated by SND1 or VND7.
Project description:Staphylococcal nuclease domain-containing protein 1 (SND1) is overexpressed in human hepatocellular carcinoma (HCC) and positively regulates development and progression of HCC. We established stable clones expressing SND1 shRNA in QGY-7703 cells and analyzed the gene expression profiles of a control clone and two SND1 knockdown clones to check what genes are regulated by SND1. Steady-state proliferating cells were collected for RNA extraction and Affymetrix microarray hybridization. Three biological replicates each of a control clone and 2 SND1 knockdown clones.
Project description:The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a key regulator of xylem vessel differentiation. In order to identify direct target genes of VND7, we performed global transcriptome analysis using Arabidopsis transgenic lines in which VND7 activity could be induced post-translationally. This analysis identified 63 putative direct target genes of VND7, which encode a broad range of proteins, such as transcription factors, IRREGULAR XYLEM proteins and proteolytic enzymes, known to be closely associated with xylem vessel formation. Recombinant VND7 protein binds to several promoter sequences present in candidate direct target genes: specifically, in the promoter of XYLEM CYSTEINE PEPTIDASE1, two distinct regions were demonstrated to be responsible for VND7 binding. We also found that expression of VND7 restores secondary cell wall formation in the fiber cells of inflorescence stems of nst1 nst3 double mutants, as well as expression of NAC SECONDARY WALL THICKENING PROMOTING FACTOR3 (NST3, however, the vessel-type secondary wall deposition was observed only as a result of VND7 expression. These findings indicated that VND7 upregulates, directly and/or indirectly, many genes involved in a wide range of processes in xylem vessel differentiation, and that its target genes are partially different from those of NSTs.
Project description:Staphylococcal nuclease domain-containing protein 1 (SND1) is overexpressed in human hepatocellular carcinoma (HCC) and positively regulates development and progression of HCC. We established stable clones expressing SND1 shRNA in QGY-7703 cells and analyzed the gene expression profiles of a control clone and two SND1 knockdown clones to check what genes are regulated by SND1.
Project description:Regulation of viral RNA biogenesis is fundamental to productive SARS-CoV-2 infection. To characterize host RNA-binding proteins (RBPs) involved in this process, we biochemically identified proteins bound to genomic and subgenomic SARS-CoV-2 RNAs. We find that the host protein SND1 binds the 5ʹ end of negative-sense viral RNA and is required for SARS-CoV-2 RNA synthesis. SND1-depleted cells form smaller replication organelles and display diminished virus growth kinetics. We discover that NSP9, a viral RBP and direct SND1 interaction partner, is covalently linked to the 5ʹ ends of positive and negative-sense RNAs produced during infection. These linkages occur at replication-transcription initiation sites, consistent with NSP9 priming viral RNA synthesis. Mechanistically, SND1 remodels NSP9 occupancy and alters the covalent linkage of NSP9 to initiating nucleotides in viral RNA. Our findings implicate NSP9 in the initiation of SARS-CoV-2 RNA synthesis and unravel an unsuspected role of a cellular protein in orchestrating viral RNA production.
Project description:Staphylococcal nuclease Tudor domain containing 1 (SND1) protein is an oncogene that “reads” methylarginine marks through its Tudor domain. Specifically, it recognizes methylation marks deposited by protein arginine methyltransferase 5 (PRMT5), which is also known to promote tumorigenesis. SND1 is a known driver of hepatocellular carcinoma, but it is unknown if the Tudor domain is needed to drive this disease. We sought to identify the biological role of the SND1 Tudor domain in normal and tumorigenic settings. To do so, we developed two genetically engineered SND1 mouse models, namely a knockout (Snd1 KO) and a Snd1 Tudor domain mutated (Snd1 KI) mouse. Transcriptome analysis of normal KO and KI liver samples reveals a role for the SND1 Tudor domain in regulating expression of major acute phase proteins (APPs) and genes involved in the unfolded protein response (UPR), which could provide mechanistic insight into SND1’s functions in a tumor setting. These processes may provide insight into how SND1 functions as an oncogene. These results support the use of PRMT5 inhibitors, and the development of small molecule inhibitors that target the SND1 Tudor domain, as novel treatments for HCC.
Project description:PyMT tumor cells with indicated status of Mtdh and Snd1 were treated with camptothecin (CPT) and the transcirptome profiles were determined and compared two sets of experiments: (1) vector control vs Snd1-KD under CPT treament (2) PyMT/Mtdh-KO cells reconstituted with either WT or Snd1-binding deficient mutant Mtdh (W391D) under CPT treatment
Project description:The RNA-binding protein Snd1 can regulate gene expression through various mechanisms, including microRNA decay. Here we have investigated microRNA expression in livers of WT and Snd1 knockout (KO) mice
Project description:We have mapped m6A sites and endogenous SND1 binding sites in the viral and cellular transcriptome using TREx BCBL1-Rta cells. In addition, we have depleted SND1 in TREx BCBL1-Rta cells and BCBL1 cells and analyzed their RNA expression profile both during latency and lytic replication.