Project description:Cilia and flagella serve as cellular antennae that translate sensory information into cellular responses. In sperm, a single chemoattractant molecule triggers signaling events that evoke a Ca2+ response and chemotactic steering. Key components of the chemotactic signaling pathway from sperm of the sea urchin Arbacia punctulata were investigated. Shotgun proteomics employing SDS-PAGE LC-MS/MS and MudPIT provided the proteome inventory of sperm flagella.
Project description:A total of 132 differentially expressed genes (DEGs) regulated by the RcsB have been identified, of which 114 were up-regulated and 18 were down-regulated. Analyses of the GO annotation and KEGG enrichment led us to focus on the role of RcsB in the inhibition of chemotactic behavior, flagella biosynthesis and bacterial infection in Y. enterocolitica. Overall, the information provided in this study complements our understanding of Rcs phosphorelay in the regulation of Y. enterocolitica pathogenicity, and, simultaneously, provides clues to additional roles of the Rcs system in other members of family Enterobacteriaceae.
2020-04-27 | GSE149365 | GEO
Project description:Natural bacterial community chemotactic to the polysaccharide laminarin
Project description:The obligate intracellular protozoan Toxoplasma gondii exploits the trafficking of mononuclear phagocytes for systemic dissemination. We report that, upon T. gondii infection, macrophages initiate expression of transcription factors normally attributed to DCs, upregulate the expression of Ccr7 with a chemotactic response, and perform systemic migration when adoptively transferred into mice. We identify the parasite effector GRA28, which is secreted into the host cell nuclei, as driving the chemotactic migratory activation of parasitized macrophages. To gain insight about the molecular role played by GRA28 in this phenomenon, we characterized its interactome.
Project description:We extracted RNA from NC and KO-Toe1 differentiated C17.2 cells for high-throughput transcriptomic sequencing. In differentiated C17.2 cells, Toe1 primarily affected biological functions including peptidase activity, chemotactic factors, the ECM, and the TNF signaling pathway.
Project description:In this study, we investigated the functional role of NLRP2 in proximal tubular epithelial cells by overexpressing it in human conditionally immortalized cells obtained from urine of a healthy subject. We found that NLRP2 markedly upregulates proinflammatory and chemotactic responses as well as downregulates interferon-mediated signaling pathways.
Project description:<p>The capacity of planktonic marine microorganisms to actively seek out and exploit microscale chemical hotspots has been widely theorized to affect ocean-basin scale biogeochemistry, but has never been examined comprehensively in situ among natural microbial communities. Here, using a field-based microfluidic platform to quantify the behavioural responses of marine bacteria and archaea, we observed significant levels of chemotaxis towards microscale hotspots of phytoplankton-derived dissolved organic matter (DOM) at a coastal field site across multiple deployments, spanning several months. Microscale metagenomics revealed that a wide diversity of marine prokaryotes, spanning 27 bacterial and 2 archaeal phyla, displayed chemotaxis towards microscale patches of DOM derived from 10 globally distributed phytoplankton species. The distinct DOM composition of each phytoplankton species attracted phylogenetically and functionally discrete populations of bacteria and archaea, with 54% of chemotactic prokaryotes displaying highly specific responses to the DOM derived from only one or two phytoplankton species. Prokaryotes exhibiting chemotaxis towards phytoplankton-derived compounds were significantly enriched in the capacity to transport and metabolize specific phytoplankton-derived chemicals, and displayed enrichment in functions conducive to symbiotic relationships, including genes involved in the production of siderophores, B vitamins and growth-promoting hormones. Our findings demonstrate that the swimming behaviour of natural prokaryotic assemblages is governed by specific chemical cues, which dictate important biogeochemical transformation processes and the establishment of ecological interactions that structure the base of the marine food web.</p>
Project description:We used single-cell RNA-seq to reconstruct differentiation paths of cardiac progenitors in two sequential waves during early heart development. Further analysis identified six major cell types and multiple differentiation trajectories of cardiac progenitors derived from distinct heart fields. We also constructed TF regulatory networks controlling SHF CPC differentiation. Interlineage crosstalk through signaling pathways and chemotactic guidance played a potent role in SHF CPC deployment. The mechanisms regulating SHF CPC migration and differentiation was further confirmed by Nkx2-5 enhancer knock out. Our work provides a cardiac lineage hierarchy and new insights into SHF CPC development. Mechanistically, NKX2-5 directly bound the Cxcr2 genomic locus and activated its transcription.