Project description:This is a deterministic model built using COPASI. It simulates the toxin activity of K1 toxin produced by Saccharomyces cerevisiae from inoculation through to toxin-induced cell death of a population of susceptible S.cerevisiae. The model can be used to track the kinetics of toxin action via either its primary action pathway seen at high concentrations or its secondary action pathway, via induced apoptosis, seen at low concentrations.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of transfected NC K1 cells and transfected si-NEAT1_2 K1 cells. The goals of this study are to analysis the different mRNA expression between transfected NC K1 cells and transfected si-NEAT1_2 K1 cells. Quantitative reverse transcription polymerase chain reaction (qRT–PCR) methods and to evaluate protocols for optimal high-throughput data analysis. We performed mRNA-seq in the NEAT1_2 knockdown group and NC group in the K1 cell line. We found that after knockdown of NEAT1_2, 615 mRNAs were upregulated and 2364 mRNAs were downregulated.
Project description:Rickettsia spp. can cause mild to severe human disease. These intracellular bacteria are associated with arthropods, nematodes and trematodes, and usually, are efficiently transmitted transovarially to the progeny of the invertebrate host. We recently demonstrated foreign gene acquisition by lateral gene transfer in Rickettsia genomes. The unexpected presence of laterally transferred toxin-antitoxin (TA) genetic elements (including vapBC) in several Rickettsia genomes has not been connected with the pathogenic process or the host-bacteria relationship. We suspect that vapBC are selfish genetic elements that addict eukaryotic hosts to Rickettsia. We identified a statistical link between the transovarial transmission of Rickettsia in invertebrate hosts and the presence of TA operons, specifically vapBC, in the Rickettsia genome. These TA are neighboring to type IV secretion genes. Tunel assays and whole-genome expression of infected cells showed that antibiotic eradication of TA-containing Rickettsia from the host in cell culture initiates a proapoptotic program. Rickettsia VapC toxins inhibit the growth of transformed Escherichia coli and Saccharomyces cerevisiae. Rickettsia toxin presents in vitro RNase activity. Annexin-V staining and time-lapse video showed that intracytoplasmic injections of VapC toxins in cells cause apoptosis. These data demonstrate that host cells may develop a dependence on Rickettsia spp. expressing the vapBC operon. This would constitute a new evolutionary “mafia strategy” of intracellular bacteria based on host addiction.
Project description:High-throughput data analysis was performed to identify the differentially expressed circRNAs in K1 control cell and AhR antagonist treated K1 cells. In total, 45 differentially expressed circRNAs were found.
Project description:The RNA interference (RNAi) pathway is found in most eukaryotic lineages but curiously is absent in others, including that of Saccharomyces cerevisiae. Here, we show that reconstituting RNAi in S. cerevisiae causes loss of a beneficial dsRNA virus, known as killer virus. Incompatibility between RNAi and killer viruses extends to other fungal species, in that RNAi is absent in all species known to possess dsRNA killer viruses, whereas killer viruses are absent in closely related species that retained RNAi. Thus, the advantage imparted by acquiring and retaining killer viruses explains the persistence of RNAi-deficient species during fungal evolution. Employ high-throughput sequencing of endogenous small RNAs from Saccharomyces cerevisiae wild-type and RNAi-reconstituted strains.
Project description:Rickettsia spp. can cause mild to severe human disease. These intracellular bacteria are associated with arthropods, nematodes and trematodes, and usually, are efficiently transmitted transovarially to the progeny of the invertebrate host. We recently demonstrated foreign gene acquisition by lateral gene transfer in Rickettsia genomes. The unexpected presence of laterally transferred toxin-antitoxin (TA) genetic elements (including vapBC) in several Rickettsia genomes has not been connected with the pathogenic process or the host-bacteria relationship. We suspect that vapBC are selfish genetic elements that addict eukaryotic hosts to Rickettsia. We identified a statistical link between the transovarial transmission of Rickettsia in invertebrate hosts and the presence of TA operons, specifically vapBC, in the Rickettsia genome. These TA are neighboring to type IV secretion genes. Tunel assays and whole-genome expression of infected cells showed that antibiotic eradication of TA-containing Rickettsia from the host in cell culture initiates a proapoptotic program. Rickettsia VapC toxins inhibit the growth of transformed Escherichia coli and Saccharomyces cerevisiae. Rickettsia toxin presents in vitro RNase activity. Annexin-V staining and time-lapse video showed that intracytoplasmic injections of VapC toxins in cells cause apoptosis. These data demonstrate that host cells may develop a dependence on Rickettsia spp. expressing the vapBC operon. This would constitute a new evolutionary M-bM-^@M-^\mafia strategyM-bM-^@M-^] of intracellular bacteria based on host addiction. Fresh cells from the human microvascular endothelial cell line (HMEC-1) [26] were infected with R. felis California-2 strain in the presence and absence of antibiotics, at a rate of 5 bacteria per eukaryotic cell. Then, we added or not antibiotics (chloramphenicol 50 M-BM-5g/ml or doxycycline to 40 M-BM-5g/ml) in both experimental (R.felis-infected) and control, mock-infected cells for 6 hours. The cells were harvested and RNA was extracted using the RNeasy Mini Kit (Qiagen). DNA contamination was removed using the Turbo DNA-free Kit (Ambion). RNA were labeled using the Quick Amp Labeling Kit One-color (Agilent) and hybridized onto a Whole Human Genome Microarray, 4x44K (Agilent) as recommended by the manufacturer. Arrays were scanned with DNA Microarray Scanner (Agilent), and data were extracted using Feature Extractor (Agilent).
Project description:In yeast, the extrachromosomal genetic element [KIL-d] alters killer activity of M double stranded RNA killer virus and confers cell resistance against the killer virus. However, its underlying mechanism and the molecular nature of [KIL-d] is unknown. We found [KIL-d] selectively increases the rate of de novo mutation in the killer toxin gene of the viral genome. To verify this hypotesis, we performed deep sequence analysis to calculate mutation rate.
Project description:RAD21 ChIA-PET in human K1 cells For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODE_Data_Use_Policy_for_External_Users_03-07-14.pdf
Project description:The number and type of synthetic chemicals that are being produced worldwide continues to increase significantly. While these industrial chemicals provide numerous benefits, there is no doubt that some have potential to damage the environment and health. Toxicity must be evaluated and use must be carefully controlled and monitored in order to minimize potential damage. DNA microarray technology has become an important new technique in toxicology. We are using the yeast Saccharomyces cerevisiae as a model organism for toxicological study because it is a simple, fast-growing eukaryote that has been thoroughly characterized. In order to evaluate toxicity by newly synthesized or mixture chemicals, toxicity-induced gene expression alteration profiles by known chemicals should be collected. In our study, cells need to be exposed with same experimental cellular condition, semi lethal (IC50), respectively. In the case of T-2 toxin(CAS; 21259-20-1), the exposure dose was decided as 108ppm by growth curve with continuously diluted exposure. T-2 toxin has beenn shpwn to cause variety of toxic effect including inhibition of DNA, RNA and protein synthesis. Keywords: stress response