Project description:Plants are targets of volatile organic compounds (VOCs) released as a part of plant-plant communication, within-plant self-signaling and plant-microbe interactions. Therefore, understanding VOC perception and downstream signaling is vital for unraveling the mechanisms behind information exchange in plants, which remain largely unexplored. Using the hormone-like function of volatile terpenoids in reproductive organ development as a system with a visual marker for communication, we demonstrated that among the four petunia karrikin-insensitive receptors, PhKAI2ia stereo-specifically perceives the (-)-germacrene D signal, triggering a karrikin-like signaling cascade. This study provides new insights into plant olfaction, uncovers the role(s) of the unique intermediate clade of KAI2 receptors, illuminates the involvement of KAI2ia-dependent signaling pathway in volatile communication and gives insight into the long-standing question about the nature of potential endogenous karrikin-like ligand(s).
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent of primary effusion lymphoma (PEL). All PEL cell lines are infected with KSHV, and 70% are co-infected with Epstein-Barr Virus (EBV). KSHV reactivation from latency requires promoter-specific transactivation by the KSHV Rta protein through interactions with RBP-Jk (CSL), the cellular DNA binding component of the Notch signal transduction pathway. EBV transformation of primary B cells requires EBV nuclear antigen (EBNA)-2 to interact with RBP-Jk to direct the latent viral and cellular gene expression program. Although KSHV Rta and EBV EBNA-2 both require RBP-Jk for transactivation, previous studies have suggested that RBP-Jk-dependent transactivators do not function identically. We have found that the EBV latent protein LMP-1 is expressed in less than 5% of KSHV+/EBV+ PEL cells, but is induced in an Rta-dependent fashion when KSHV reactivates. KSHV Rta transactivates the EBV latency promoters in an RBP-Jk-dependent fashion and forms a ternary complex with RBP-Jk on the promoters. In B cells that are conditionally transformed by EBV alone, we show that KSHV Rta complements a short-term EBNA2 growth deficiency in an autocrine/paracrine manner. Complementaton of EBNA2-deficiency by Rta depends on RBP-Jk and LMP-1, and Rta transactivation is required for optimal growth of KSHV+/EBV+ PEL lines. Our data suggest that Rta can contribute to EBV-driven cellular growth by transactivating RBP-Jk-dependent EBV latency genes. However, our data also suggest that EBNA2 and Rta induce distinct alterations in the cellular proteomes that contribute to growth of infected cells. EREB2-5 cells were transfected and grown in the presence or absence of β-estradiol, as described. Seven days post-transfection, protein extracts were prepared, and 200 ugs. of each were analyzed using the RayBio Human Apoptosis Antibody Array Kit (RayBiotech) as per manufacturers suggestions. The membranes were exposed to autoradiography film for different times to detect the chemiluminescent signals. Images with signals in linear range were quantitated using the program ImageJ [59]. For each membrane, signals from the negative control spots were averaged, and then subtracted from each of the other spots. A signal was considered valid if its value exceeded both its average local background, and the average of all valid negative control values. Valid signals were normalized using the positive control spots (for cellular BID protein). Fold change in signals for each spot were quantitated by dividing by the valid signals for each corresponding spot on the minus β-estradiol membrane. Average fold change, and standard deviation, were calculated for each protein.
Project description:Systemic acquired resistance (SAR) involves the generation of systemically transported signal that arms distal plant parts against secondary infections. We show that two phased 21-nucleotide (nt) trans-acting small interfering RNA3a RNAs (tasi-RNA) derived from TAS3a and synthesized within 3 hours of pathogen infection are the early mobile signal in SAR. TAS3a undergoes alternate polyadenylation, resulting in the generation of 555- and 367-nt transcripts. The 555-nt transcripts likely serves as the sole precursor for tasi-RNAs D7 and D8, which cleave Auxin response factors (ARF) 2, 3, and 4 to induce SAR. Conversely, increased expression of ARF3 represses SAR. Knockout mutations in TAS3a or RNA silencing components required for tasi-RNA biogenesis compromise SAR without altering levels of known SAR-inducing chemicals. Both tasi-ARFs and the 367-nt transcripts are mobile and transported via plasmodesmata. Together, we show that tasi-ARFs are the early mobile signal in SAR.
Project description:DNA methylation profiling of NeuN+sorted neuronal nuclei from post-mortem brain tissue of Multiple Sclerosis (MS) patients (n=10) (MS) and non-neurological controls (n=7) (non-MS). Genomic DNA was subjected to conventional BS-treatment as well as oxidative BS (oxBS)-conversion using TrueMethylTM 96 kit of CEGXTM (Cambridge Epigenetix Limited) to allow for subsequent detection of hydroxymethylation (5hmC = BS - oxBS).
Project description:This project aims at the detection of specific patterns of miRNAs in peripheral blood samples of MS patients. As controls, blood of donors without known affection have been tested. Using the miRNA patterns we hope to detect a diagnostic pattern for the non-invasive diagnosis of MS.
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiologic agent of primary effusion lymphoma (PEL). All PEL cell lines are infected with KSHV, and 70% are co-infected with Epstein-Barr Virus (EBV). KSHV reactivation from latency requires promoter-specific transactivation by the KSHV Rta protein through interactions with RBP-Jk (CSL), the cellular DNA binding component of the Notch signal transduction pathway. EBV transformation of primary B cells requires EBV nuclear antigen (EBNA)-2 to interact with RBP-Jk to direct the latent viral and cellular gene expression program. Although KSHV Rta and EBV EBNA-2 both require RBP-Jk for transactivation, previous studies have suggested that RBP-Jk-dependent transactivators do not function identically. We have found that the EBV latent protein LMP-1 is expressed in less than 5% of KSHV+/EBV+ PEL cells, but is induced in an Rta-dependent fashion when KSHV reactivates. KSHV Rta transactivates the EBV latency promoters in an RBP-Jk-dependent fashion and forms a ternary complex with RBP-Jk on the promoters. In B cells that are conditionally transformed by EBV alone, we show that KSHV Rta complements a short-term EBNA2 growth deficiency in an autocrine/paracrine manner. Complementaton of EBNA2-deficiency by Rta depends on RBP-Jk and LMP-1, and Rta transactivation is required for optimal growth of KSHV+/EBV+ PEL lines. Our data suggest that Rta can contribute to EBV-driven cellular growth by transactivating RBP-Jk-dependent EBV latency genes. However, our data also suggest that EBNA2 and Rta induce distinct alterations in the cellular proteomes that contribute to growth of infected cells.
Project description:We enriched endothelial cells and other bone marrow cells in both fetal and adult stage to investigate Wnt signaling interaction using targeted scRNA-seq analysis. This analysis facilitate identification of sources of Wnt ligands and detection of Wnt receptor expression in bone marrow. The comparison of fetal and adult stage reveals differences of Wnt signaling in fetal and adult BM.
Project description:Plants adapt to environmental changes by adjusting growth and defense, and the role of epigenetic modifications in this process is unclear. Sensing and adjusting to environmental changes are more important in certain tissues such as epidermis, vasculature, meristem, and reproductive tissues. These tissues possess sensory plastids that are specialized in environmental sensing. We show perturbation of four sensory plastid proteins MSH1, PPD3, CUE1, and SAL1 induce gene expression and DNA methylation changes targeted to networks associated to environmental sensing, with significant overlap with hda6-induced CHG hypermethylated genes at 12-hr daylength. At 16-hr daylength, hda6 loses CHG hypermethylation in gene body, and sensory plastid mutants have weaker phenotypes and DNA methylation- and gene expression- associated gene networks. We show daylength-responsive epistatic interaction between sensory plastid mutants with hda6. We also show that hda6 mutation confers daylength memory and, with msh1, enhanced tolerance to heat stress and biotic stress. These results suggest that HDA6 mediates programmed adjustments in plant phenotype triggered by sensory plastid-to-nucleus retrograde signaling in response to daylength and environmental cues.