ABSTRACT: identification and characterization of class III antiviral lanthipeptide arrested at various stages of sequencial modification and maturation.
Project description:ApoCIII and IP-SampleStream-MS raw files
ApoC-III proteoform characterization and post-translational modification (PTM) mapping, intact mass spectra were recorded and fragmentation data was acquired
Project description:Dicer is an RNase III-family endoribonuclease and haploinsufficient tumor suppressor that is required for the biogenesis of miRNAs, yet in vivo structure-function characterization of its RNase IIIA and IIIB domains have not been reported. In murine Dicer knockout fibroblasts, we expressed human Dicer with point mutations in the RNase III, helicase, and PAZ domains and characterized miRNA expression by Northern blot and massively parallel sequencing of small RNAs. Inactivation of the RNase IIIA or IIIB domain blocked maturation of miRNAs derived from the 3’ or 5’ arms of miRNA precursors, respectively, and resulted in altered miRNA expression profiles. Small RNAs from murine mesenchymal stem cells (MScs) with and without Dicer (WT:Dicer f/f, KO:Dicer -/-, KO transfected with various hsDicer point mutants) were analyzed.
Project description:Lipids, such as phosphoinositides (PIPs) and diacylglycerol (DAG), are important signaling intermediates involved in cellular processes such as T cell receptor (TCR)-mediated signal transduction. Here we report identification and quantification of PIP, PIP2 and DAG from crude lipid extracts. Capitalizing on the different extraction properties of PIPs and DAGs allowed us to efficiently recover both lipid classes from one sample. Rapid analysis of endogenous signaling molecules was performed by nano-electrospray ionization tandem mass spectrometry (nano-ESI MS/MS), employing lipid class-specific neutral loss and multiple precursor ion scanning for their identification and quantification. Profiling of DAG, PIP and PIP2 molecular species in primary human T cells before and after TCR stimulation resulted in a two-fold increase in DAG levels with a shift towards 1-stearoyl-2-arachidonoyl-DAG in stimulated cells. PIP2 levels were slightly reduced, while PIP levels remained unchanged.
Project description:Investigation of gene expression level changes in snapdragon petals and sepals during flower development The flower developmental stages analyzed in this study are representative of distinct developmental events: (i) preanthesis, (ii) anthesis, (iii) maturation and (iv) presenescence and are further described in the accompanying article.
Project description:Investigation of gene expression level changes in snapdragon petals and sepals during flower development The flower developmental stages analyzed in this study are representative of distinct developmental events: (i) preanthesis, (ii) anthesis, (iii) maturation and (iv) presenescence and are further described in the accompanying article. A 24 chip study using total RNA recovered from samples of petal and sepal tissue of Antirrhinum majus cv. Maryland True Pink harvested at four different stages of flower development, namely (i) preanthesis (three days before flower opening=d-3), (ii) anthesis (day of flower opening=d1), (iii) maturation (four days after flower opening=d4) and (iv) presenescence (seven days after flower opening=d7). Three separate samples were extracted per tissue and developmental stages. Each chip measures the expression level of 11,959 ESTs from Antirrhinum majus cv. Maryland True Pink with up to six 60-mer probes per target.
Project description:How epigenetics is involved in the transition from seed maturation to seed germination largely remains elusive. To uncover the possible role of epigenetics in gene expression during the transition from seed maturation to seed germination in soybean, the transcriptome of cotyledons from four stages of soybean seed maturation and germination, including mid-late maturation, late maturation, seed dormancy and seed germination, were profiled by Illumina sequencing. For the genes that are quantitatively regulated at the four stages, two antagonistic epigenetic marks, H3K4me3 and H3K27me3, together with the binding of RNA polymerase II, were investigated at the four stages by chromatin immunoprecipitation (ChIP). For 10 out of 16 genes examined, the relative enrichment of histone modification marks (H3K4me3 and H3K27me3) and RNA polymerase II binding on their promoter regions correlates well with their relative expression levels at four stages, suggesting the involvement of epigenetics in transcriptional regulation. A striking finding is that seed germination-specific genes start to show open chromatin (H3K4me3) during late seed maturation although their transcripts do not accumulate, which is further supported by RNA polymerase II binding. Together, our results provide the first evidence that seed germination genes can be primed for transcription (open chromatin and RNA polymerase II binding) during seed maturation, highlighting that the transition from seed maturation to seed germination starts at late seed maturation stages at both the genetic and epigenetic levels. Illumina sequencing of transcripts from cotyledons of mid-maturation (B1 stage) and late maturation (AA1 stage) seeds, whole dry seeds, and cotyledons of seedlings six days after imbibition.
Project description:Results from experiments done on knock-down of adaxial class III HD ZIP genes, using overexpression of miR165a, in shoot meristem show that Class III HD-ZIP genes act generally to repress the formation of new growth axes where they are expressed. This study explored the genes directly regualted by miRNAs as well as indirectly regulated by class III HD-ZIPs.
Project description:Results from experiments done on knock-down of adaxial class III HD ZIP genes, using overexpression of miR165a, in shoot meristem show that Class III HD-ZIP genes act generally to repress the formation of new growth axes where they are expressed. This study explored the genes directly regualted by miRNAs as well as indirectly regulated by class III HD-ZIPs.