Electrical polarization enables integrative quality control during bacterial differentiation into spores
Teja Sirec, Jonatan M. Benarroch, Pauline Buffard, Jordi Garcia-Ojalvo, Munehiro Asally
Quality control of offspring is important for the survival of cells. However, the mechanisms by which quality of offspring cells may be checked while running genetic programs of cellular differentiation remain unclear. Here we investigated quality control during sporulating in Bacillus subtilis by combining single-cell time-lapse microscopy, molecular biology and mathematical modelling. Our results revealed that the quality control via premature germination is coupled with the electrical polarization of outer membranes of developing forespores.
The MK2 cascade regulates mGluR-dependent synaptic plasticity and reversal learning
Privitera L, Hogg EL, Gaestel M, Wall MJ and Corrêa SAL
The ability to either erase or update the memories of a previously learned spatial task is an essential process that is required to modify behaviour in a changing environment. Current evidence suggests that the neural representation of such cognitive flexibility involves the balancing of synaptic potentiation (acquisition of memories) with synaptic depression (modulation and updating previously acquired memories). Here we demonstrate that the p38 MAPK/MAPK-activated protein kinase 2 (MK2) cascade is required to maintain the precise tuning of long-term potentiation and long-term depression at CA1 synapses of the hippocampus which is correlated with efficient reversal learning. ndings from this study suggest that the mGluR-p38-MK2 cascade is important for cognitive flexibility by regulating LTD amplitude and the priming of LTP.
Age- and Experience-Related Plasticity of ATP-Mediated Signaling in the Neocortex
Ulyana Lalo, Alexander Bogdanov and Yuriy Pankratov
There is growing recognition of the important role of interaction between neurons and glial cells for brain longevity. The extracellular ATP have been shown to bring significant contribution into bi-directional glia-neuron communications, in particular into astrocyte-driven modulation of synaptic plasticity. To elucidate a putative impact of brain aging on neuron-glia networks, we explored the aging-related plasticity of the purinoreceptors-mediated signaling in cortical neurons and astrocytes. We investigated the age- and experience-related alterations in purinergic components of neuronal synaptic currents and astroglial calcium signaling. Our results strongly support the physiological importance of ATP-mediated signaling for glia-neuron interactions and brain function
Joseph Christie-Oleza publications
Understanding microbial community dynamics to improve optimal microbiome selection
Robyn J. Wright, Matthew I. Gibson and Joseph A. Christie-Oleza
Artificial selection of microbial communities that perform better at a desired process has seduced scientists for over a decade, but the method has not been systematically optimised nor the mechanisms behind its success, or failure, determined. We successfully selected for microbial communities with enhanced chitinase activities but found that continuous optimisation of incubation times between selective transfers was of utmost importance. The analysis of the community composition revealed fundamental aspects in microbial ecology: when incubation times between transfers were optimal, the system was dominated by Gammaproteobacteria before being succeeded by cheating, cross-feeding and grazing organisms.. A comprehensive understanding of microbial community dynamics will improve the success of future community selection studies. Microbiome. June 2019
Identification of proteins and genes expressed by Methylophaga thiooxydans during growth on dimethylsulfide and their presence in other members of the genus
Eileen Kröber, Hendrik Schafer
Dimethylsulfide is a volatile organic sulfur compound that provides the largest input of biogenic sulfur from the oceans to the atmosphere, and thence back to land, constituting an important link in the global sulfur cycle. Microorganisms degrading DMS affect fluxes of DMS in the environment, but the underlying metabolic pathways are still poorly understood. Methylophaga thiooxydans is a marine methylotrophic bacterium capable of growth on DMS as sole source of carbon and energy. We identified genes expressed during growth on dimethylsulfide and methanol to refine our knowledge of the metabolic pathways that are involved in DMS and methanol degradation in this strain. The results suggested that the pathways of DMS-utilization and subsequent C1 and sulfur oxidation are not conserved across Methylophaga isolates that degrade methylated sulfur compounds.
SMA-PAGE: A new method to examine complexes of membrane proteins using SMALP nano-encapsulation and native gel electrophoresis
Pollock NL, Rai M, Simon KS, Hesketh SJ, Teo ACK, Parmar M, Sridhar P, Collins R, Lee SC, Stroud ZN, Bakker SE, Muench SP, Barton CH, Hurlbut G, Roper DI, Smith CJI, Knowles TJ, Spickett CM, East JM, Postis V, Dafforn TR
Most membrane proteins function through interactions with other proteins in the phospholipid bilayer, the cytosol or the extracellular milieu. Understanding the molecular basis of these interactions is key to understanding membrane protein function and dysfunction. Here we demonstrate for the first time how a nano-encapsulation method based on styrene maleic acid lipid particles (SMALPs) can be used in combination with native gel electrophoresis to separate membrane protein complexes in their native state. Our results provide a novel and elegant method for investigating membrane protein complexes in a native state.