Project description:Purpose:To uncover the related mechanisms underlie virulence attenuation of Brucella canis MucR mutant strain. Methods:Three Brucella canis RM6/66 strains and three Brucella canis ΔmucR strains were grown in TSB at 37℃ until the log phase was reached, total RNA was isolated using the TRIzol according to the manufacturer’s instructions.The sequencing library of each RNA sample was prepared by using NEB Next Ultra Directional RNA Library Prep Kit for Illumina as recommended by the manufacturer. An Illumina platform was used to perform the transcriptome sequencing. Results: The results revealed that expressions of 694 genes were significantly different between RM6/66 and ΔmucR. Data analysis showed that in the COG term, the different expressed genes involved in translation, ribosomal structure and biogenesis, signal transduction mechanisms, energy production and conversion, intracellular trafficking, secretion, and vesicular transport, and extracellular structures were significantly affected. Pathway enrichment analysis indicated that the genes involved in ribosome, oxidative phosphorylation, aminoacyl-tRNA biosynthesis and protein export were significantly enriched.
Project description:mRNA translation plays a major role in homeostasis, whereas its dysregulation underpins a variety of pathological states including cancer, metabolic syndrome and neurological disorders. Ternary complex (TC) and eIF4F complex assembly are two major rate-limiting steps in translation initiation that are thought to be regulated by eIF2α phosphorylation, and the mTOR/4E-BP pathway, respectively2. However, how TC and eIF4F assembly are coordinated remains largely unknown. Using polysome-profiling, we show that on a genome-wide scale mTOR suppresses translation of mRNAs, which are translationally activated under short-term ER stress when TC recycling is attenuated by eIF2α phosphorylation. During acute nutrient or growth factor stimulation, mTORC1 induces eIF2β phosphorylation, which increases recruitment of NCK1 to eIF2, decreases eIF2α phosphorylation and bolsters TC recycling. Accordingly, eIF2β appears to act as a previously unidentified mediator of mTORC1 on protein synthesis and proliferation. In addition, we demonstrate a formerly undocumented role for CK2 in regulation of translation initiation, whereby CK2 stimulates phosphorylation of eIF2β and simultaneously bolsters eIF4F complex assembly via the mTORC1/4E-BP pathway. These findings imply a previously unrecognized mode of translation regulation whereby mTORC1 and CK2 coordinate TC and eIF4F complex assembly to stimulate cell proliferation.
Project description:CK2 binds to actively transcribed regions in the genome and regulates transcriptional elongation. Identification of genome-wide binding sites of CK2?, and examination of the effect of Pol II binding upon CK2 inhibition in LNCaP cells
