Project description:In this study, a cross species hybridization (CSH) approach was used to evaluate whole transcriptome changes during carotenoid accumulation in the storage root of carrot (Daucus carota). Carotenoids are isoprenoid compounds providing red, yellow and orange color to plants. Previous gene expression analyses of carotenoid accumulation in non-model plant species have primarily used a candidate gene approach. Since global transcriptome analyses require extensive genome sequence, in the absence of these genomic resources an alternate approach uses platforms developed for model plant species. To assess transcriptome patterns associated with carotenoid pigmentation in carrot storage root, two carrot sibling inbred lines, B8788, true breeding for orange color and B8750, true breeding for white root color, were hybridized to the Medicago Affymetrix GeneChip microarray. Near isogenic recombinant inbred lines B8788 and B8750, derived from a cross between white rooted wild carrot (QAL) and orange-rooted B493 were used for comparative analyzes to minimize background genetic differences. B8788 is true breeding for orange color whereas B8750 is true breeding for white storage root color. Carrots were grown in three pots for each genotype under greenhouse conditions and carrots were selected arbitrarily from these pots for harvest. Roots were harvested at approximately 11 weeks post planting when carotenoid accumulation becomes apparent in the storage root. Storage root tissue from sixteen individual carrot roots was pooled into three one-gram tissue pools of four carrots for each genotype.
Project description:Genome-wide transcription factor binding profiles provide valuable insights into hematopoietic development and malignancies. Today, advanced computational methods exploit cis-regulatory information to predict complex gene regulatory networks controlled by transcription factors. However, these prediction methods still require large amounts of reference data or experimental expertise. Here, we present a low-requirement network-based computational framework that exploits bidirectional transcription marked regulatory elements to identify important transcription factors driving hematopoietic decision making. Using CAGE-seq we predicted TF binding and confirmed experimentally validated TF important in cell conversion strategies by exploiting bidirectional regions. Next, we applied our framework to predict driving transcription factors in induced normal erythropoiesis and early myelopoiesis, as well as in acute myeloid leukemia associated MLL-AF9-driven immortalisation. Our approach allowed the identification of experimentally validated as well as thus far unexplored transcription factors in these processes.
Project description:Microarrays transcriptomic data analyses from acute myeloid leukemia cell line OCI-AML2 and primary acute myeloid leukemia cells treated with actinomycin D.
Project description:In this study, a cross species hybridization (CSH) approach was used to evaluate whole transcriptome changes during carotenoid accumulation in the storage root of carrot (Daucus carota). Carotenoids are isoprenoid compounds providing red, yellow and orange color to plants. Previous gene expression analyses of carotenoid accumulation in non-model plant species have primarily used a candidate gene approach. Since global transcriptome analyses require extensive genome sequence, in the absence of these genomic resources an alternate approach uses platforms developed for model plant species. To assess transcriptome patterns associated with carotenoid pigmentation in carrot storage root, two carrot sibling inbred lines, B8788, true breeding for orange color and B8750, true breeding for white root color, were hybridized to the Medicago Affymetrix GeneChip microarray.
Project description:Most eukaryotic proteins are degraded by the 26S proteasome after modification with a polyubiquitin chain. Substrates lacking unstructured segments cannot be degraded directly and require prior unfolding by the Cdc48 ATPase (p97 or VCP in mammals) in complex with its ubiquitin-binding partner Ufd1-Npl4 (UN). Here, we use purified yeast components to reconstitute Cdc48-dependent degradation of well-folded model substrates by the proteasome. We show that a minimal system consists of the 26S proteasome, the Cdc48-UN ATPase complex, the proteasome cofactor Rad23, and the Cdc48 cofactors Ubx5 and Shp1. Rad23 and Ubx5 stimulate polyubiquitin binding to the 26S proteasome and the Cdc48-UN complex, respectively, allowing these machines to compete for substrates before and after their unfolding. Shp1 stimulates protein unfolding by the Cdc48-UN complex, rather than substrate recruitment. In vivo experiments confirm bidirectional substrate shuttling between the 26S proteasome and Cdc48 ATPase and identify proteins that require both machines for their degradation.
