Project description:Background: Transposable element 24 nucleotide small RNAs are not efficiently incorporated into the AGO1 protein, which is involved in endogenous RNAi and gene regulation through the microRNA and tasiRNA pathways. Results: The AGO1 protein incorporates large quantities of transposable element siRNAs when transposable elements are epigenetically activated and transcribed. The incorporation of transposable element siRNAs is at the expense of the most abundant microRNAs. These transposable element siRNAs can act as tasiRNAs, regulating genes that they have partial complementarity to. Conclusion: Transposable element small RNAs are more dynamic than previously thought. They can be incorporated into AGO1 and regulate genes. Three biological replicates of small RNA sequencing from two genotypes
Project description:Background: Transposable element 24 nucleotide small RNAs are not efficiently incorporated into the AGO1 protein, which is involved in endogenous RNAi and gene regulation through the microRNA and tasiRNA pathways. Results: The AGO1 protein incorporates large quantities of transposable element siRNAs when transposable elements are epigenetically activated and transcribed. The incorporation of transposable element siRNAs is at the expense of the most abundant microRNAs. These transposable element siRNAs can act as tasiRNAs, regulating genes that they have partial complementarity to. Conclusion: Transposable element small RNAs are more dynamic than previously thought. They can be incorporated into AGO1 and regulate genes.
Project description:Background: The small RNAs that Transposable Elements generate are vastly different when they are transcriptionally silenced compared to when they are transcriptionally activated. We performed the deep sequencing of small RNAs in a number of small RNA biogenesis mutants in both Transposable Element-silenced and Transposable Element-active epigenome backgrounds. Results: We found that Transposable Elements generate large amounts of 21-22nt siRNAs only when they are transcriptionally active. These 21-22nt siRNAs are incorporated into the AGO6 protein. Conclusion: Ago6 is the key protein that bridges the post-transcriptional degradation of Transposable Element mRNAs and the establishment of DNA methylation. Examination of flower bud small RNAs from wild type and 5 single or double mutant combinations, many of which have biological replicates. In addition, IP purification of the AGO6 protein (and mock no-antigen controls) followed by sequencing of the incorporated small RNAs. Replicate A for Col and ddm1 are submitted in GSE41755
Project description:Trichomonas vaginalis is a parasitic protist that infects the human urogenital tract. During the infection, trichomonads adhere to the host mucosa, acquire nutrients from the vaginal/prostate environment, and release small extracellular vesicles (sEVs) that contribute to the trichomonad adherenceand modulate the host-parasite communication. Approximately 40% - 70% of T. vaginalis strains harbor double-stranded RNA virus called Trichomonasvirus (TVV). Naked TVV particles have the potential to stimulate a proinflammatory response in human cells, however, the mode of TVV release from trichomonads to the environment is not clear. In this report, we showed for the first time that TVV particles are released from T. vaginalis cells within sEVs. The sEVs loaded with TVV stimulated a higher proinflammatory response of human HaCaT cells in comparison to sEVs from TVV negative parasites. Moreover, a comparison of T. vaginalis isogenic TVV plus and TVV minus clones revealed a significant impact of TVV infection on the sEV proteome and RNA cargo. Small EVs from TVV positive trichomonads contained 12 enriched and 8 unique proteins including membrane-associated BspA adhesine, and about a 2.5-fold increase in the content of small regulatory tsRNA. As T. vaginalis isolates are frequently infected with TVV, the release of TVV via sEVs to the environment represents an important factor with the potential to enhance inflammation-related pathogenesis during trichomoniasis.
Project description:Background: The small RNAs that Transposable Elements generate are vastly different when they are transcriptionally silenced compared to when they are transcriptionally activated. We performed the deep sequencing of small RNAs in a number of small RNA biogenesis mutants in both Transposable Element-silenced and Transposable Element-active epigenome backgrounds. Results: We found that Transposable Elements generate large amounts of 21-22nt siRNAs only when they are transcriptionally active. These 21-22nt siRNAs are incorporated into the AGO6 protein. Conclusion: Ago6 is the key protein that bridges the post-transcriptional degradation of Transposable Element mRNAs and the establishment of DNA methylation.
Project description:Trichomonas vaginalis, a common sexually transmitted parasite that colonizes the human urogenital tract, secretes extracellular vesicles (TvEVs) that are taken up by human cells and are speculated to be taken up by parasites as well. While the crosstalk between TvEVs and human cells has led to insight into host:parasite interactions, the role of TvEVs in infection have largely been one-sided, with little known about the effect of TvEV uptake by T. vaginalis. Approximately 11% of infections are found to be co-infections of multiple T. vaginalis strains. Clinical isolates often differ in their adherence to and cytolysis of host cells, underscoring the importance of understanding the effects of TvEV uptake within the parasite population. To address this question our lab observed the effects of EV uptake by T. vaginalis on parasite gene expression. Using RNA-seq, we showed that TvEVs upregulate expression of predicted parasite membrane proteins and identified a novel adherence factor, heteropolysaccharide binding protein (HPB2).
Project description:Transposable elements, known colloquially as “jumping genes,” constitute approximately 45% of the human genome. Cells utilize epigenetic defenses to limit transposable element jumping, including formation of silencing heterochromatin and generation of piwi-interacting RNAs (piRNAs), small RNAs that facilitate clearance of transposable element transcripts. Here we identify transposable element activation as a key mediator of neuronal death in tauopathies, a group of neurodegenerative disorders, including Alzheimer’s disease, that are pathologically characterized by deposits of tau protein in the brain. Mechanistically, we find that heterochromatin decondensation and reduction of piwi/piRNAs drive transposable element activation in tauopathy. Using genetic and pharmacological approaches in a Drosophila melanogaster model of tauopathy, we provide evidence for a causal relationship between pathogenic tau-induced heterochromatin decondensation, piwi/piRNA depletion, active transposable element obilization, and neurodegeneration. We further report a significant increase in transcripts of the endogenous retrovirus class of transposable elements in human Alzheimer’s disease and progressive supranuclear palsy, suggesting that transposable element dysregulation is conserved in human tauopathy. Taken together, our data identify heterochromatin decondensation, piwi/piRNA depletion and consequent transposable element activation as a novel, pharmacologically targetable, mechanistic driver of neurodegeneration in tauopathy.