Cell-Interactive Sensing of the Environment

摘要: Myxococcus xanthus can respond to nutrient limitation in either of two ways: (i) it enter a stationary phase, which cells grow very slowly, or (ii) stop growth and initiate the development fruiting bodies with eventual differentiation spores. In Escherichia coli Salmonella typhimurium, phase triggers into environmentally resistant rod cells, but this resistance is not manifest M. despite presence stationary-phase sigma factor, encoded by sigD. The time-ordered sequence morphological biochemical changes coordinated several signals passed between cells. One these signals, A-factor, plays an important role evaluating responding starvation. Purification A-factor was based on A-signal-dependent promoter. To identify substances that would allow A-signal-deficient mutant strain express Tn5 lacZ transcriptional fusion Ω4521 were sought from wild-type Importantly, (p)ppGpp directly assesses cell's capacity synthesize any protein for has mRNA. There as yet no evidence other starvation-sensing pathways play initiating development, even though level cyclic AMP rises twofold after induces production, requires asgA, asgB, asgC. being soluble, creates pool outside Each cell then responds total amount produced all choice response depletion nutrients critical survival.