Project description:During mammalian colonization and infection, microorganisms must be able to rapidly sense and adapt to changing environmental conditions including alterations in extracellular pH. The fungus-specific Rim/Pal signaling pathway is one process that supports microbial adaptation to alkaline pH. This cascading series of interacting proteins terminates in the proteolytic activation of the highly conserved Rim101/PacC protein, a transcription factor that mediates microbial responses that favor survival in neutral/alkaline pH growth conditions, including many mammalian tissues. We identified the putative Rim pathway proteins Rim101 and Rra1 in the human skin colonizing fungus Malassezia sympodialis. Targeted mutation of these proteins confirmed their role in M. sympodialis growth at higher pH. Additionally, comparative transcriptional analysis of the mutant strains compared to wild-type suggested mechanisms for fungal adaptation to alkaline conditions. These signaling proteins are required for optimal growth in a murine model of atopic dermatitis, a pathological condition associated with increased skin pH. Together these data elucidate both conserved and phylum-specific features of microbial adaptation to extracellular stresses.
2024-02-01 | GSE254653 | GEO
Project description:study of bacteria microorganisms
| PRJNA639016 | ENA
Project description:Study of environmental microorganisms
| PRJNA848446 | ENA
Project description:study of bacteria microorganisms
Project description:Alkaline stress has serious negative effects on citrus production. Ziyang xiangcheng (Citrus junos Sieb. ex Tanaka) (Cj) has been reported to be a rootstock that is tolerant to alkaline stress and iron deficiency. Poncirus trifoliata (Poncirus trifoliata (L.) Raf.) (Pt), the most widely used rootstock in China, is sensitive to alkaline stress. To investigate the molecular mechanism underlying the tolerance of Cj to alkaline stress, next-generation sequencing was employed to profile the root transcriptomes and small RNAs of Cj and Pt seedlings which were cultured in nutrient solution with three gradient pH. This two-regulation level data set provides a system-level view of molecular events with precise resolution. The data suggest that the auxin pathway may play a central role in inhibitory effect of alkaline stress on root growth, and the regulation of auxin homeostasis under alkaline stress was important for citrus adapting to alkaline stress. Moreover, the JA pathway shown an opposite response to alkaline stress in Cj and Pt may contributes to the differentials of root system architecture and iron deficiency tolerance between Cj and Pt. The data set provides a wealth of genomic resources and new clues for further studying the mechanisms underlying Cj that resist alkaline stress.
Project description:We performed global scale microarray analysis to identify detailed mechanisms by which sodium butyrate (SB) induce cell growth arrest and differentiation of colonic epithelial cells by using an Affymetrix GeneChip system. Colonic epithelial MCE301 cells used in this study were derived from transgenic mice harboring a tsSV40 large T-antigen. Arrested cell growth and a differentiated phenotype accompanying elevations of alkaline phosphatase activity and histone acetylation were observed in the cells treated with 2 mM SB. Of the 22,690 probe sets analyzed, approximately 2,000 genes were down- and up-regulated by a factor of 2.0 or greater in the cells treated with SB. Keywords: sodium butyrate, gene expression, colonic epithelial cell
Project description:Soil alkalinity greatly affects plant growth and crop productivity. Although RNA-Seq analyses have been conducted to investigate genome-wide gene expression in response to alkaline stress in many plants, the expression of alkali-responsive genes in rice has not previously investigated. In this study, the transcriptomic data were compared between an alkaline-tolerant [WD20342 (WD)] and an alkaline-sensitive [Caidao (CD)] rice cultivar under control and alkaline stress conditions. A total of 962 important alkali-responsive (IAR) genes from highly differentially expressed genes (DEGs) were identified, including 28 alkaline-resistant cultivar-related genes, 771 alkaline-sensitive cultivar-related genes and 163 cultivar-non-specific genes. Gene ontology (GO) analysis suggested the enrichment of IAR genes involved in response to various stimuli or stresses. According to KEGG pathway analysis, the IAR genes were related primarily to plant hormone signal transduction and biosynthesis of secondary metabolites. Additionally, among these 962 IAR genes, 74 were transcription factors and 15 occurred with differential alternative splicing between the different samples after alkaline treatment. Our results provide a valuable resource on alkali-responsive genes and should benefit the improvement of alkaline stress tolerance in rice.
Project description:The functional coupling of calcium-mediated signalling and alkaline tolerance has been demonstrated in multiple fungi. The applied relevance of such interplay extends most notably to fungal pathogens of man where the physiological pH of serum and tissues exerts considerable alkaline stress. Drugs targeting the calcium-dependent phosphatase, calcineurin, are potent antifungal agents but also perturb human calcineurin signalling, it has therefore been postulated that abrogation of fungal alkaline tolerance could offer a valuable therapeutic adjunct. To study the interdependency of pH- and calcium-mediated intracellular signalling in the major human fungal pathogen A. fumigatus, we examined the transcriptional response following exposure to 200 mM calcium chloride or alkaline pH (pH 8.0).