Towards Scalability Guidelines for Semantic Data Container Management

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The neuronal scaffold protein Shank3 mediates signaling and biological function of the receptor tyrosine kinase Ret in epithelial cells

Shank proteins, initially also described as ProSAP proteins, are scaffolding adaptors that have been previously shown to integrate neurotransmitter receptors into the cortical cytoskeleton at postsynaptic densities. We show here that Shank proteins are also crucial in receptor tyrosine kinase signaling. The PDZ domain–containing Shank3 protein was found to represent a novel interaction partner of the receptor tyrosine kinase Ret, which binds specifically to a PDZ-binding motif present in the Ret9 but not in the Ret51 isoform. Furthermore, we show that Ret9 but not Ret51 induces epithelial cells to form branched tubular structures in three-dimensional cultures in a Shank3-dependent manner. Ret9 but not Ret51 has been previously shown to be required for kidney development. Shank3 protein mediates sustained Erk–MAPK and PI3K signaling, which is crucial for tubule formation, through recruitment of the adaptor protein Grb2. These results demonstrate that the Shank3 adaptor protein can mediate cellular signaling, and provide a molecular mechanism for the biological divergence between the Ret9 and Ret51 isoform

Noninvasive preclinical and clinical imaging of liver transporter function relevant to drug-induced liver injury

Imaging technologies can evaluate many different biological processes in vitro (in cell culture models) and in vivo (in animals and humans), and many are used routinely in investigation of human liver diseases. Some of these methods can help understand liver toxicity caused by drugs in vivo in animals, and drug-induced liver injury (DILI) which arises in susceptible humans. Imaging could aid assessment of the relevance to humans in vivo of toxicity caused by drugs in animals (animal/human translation), plus toxicities observed using in vitro model systems (in vitro/in vivo translation). Technologies and probe substrates for quantitative evaluation of hepatobiliary transporter activities are of particular importance. This is due to the key role played by sinusoidal transporter mediated hepatic uptake in DILI caused by many drugs, plus the strong evidence that inhibition of the hepatic bile salt export pump (BSEP) can initiate DILI. Imaging methods for investigation of these processes are reviewed in this chapter, together with their scientific rationale, and methods of quantitative data analysis. In addition to providing biomarkers for investigation of DILI, such approaches could aid the evaluation of clinically relevant drug–drug interactions mediated via hepatobiliary transporter perturbation

Unbalanced fermentation of glycerol in Escherichia coli via heterologous production of an electron transport chain and electrode interaction in microbial electrochemical cells

Microbial electrochemical cells are an emerging technology for achieving unbalanced fermentations. However, organisms that can serve as potential biocatalysts for this application are limited by their narrow substrate spectrum. This study describes the reprogramming of Escherichia coli for the efficient use of anodes as electron acceptors. Electron transfer into the periplasm was accelerated by 183% via heterologous expression of the c-type cytochromes CymA, MtrA and STC from Shewanella oneidensis. STC was identified as a target for heterologous expression via a two-stage screening approach. First, mass spectroscopic analysis revealed natively expressed cytochromes in S. oneidensis. Thereafter, the corresponding genes were cloned and expressed in E. coli to quantify periplasmic electron transfer activity using methylene blue. This redox dye was further used to expand electron transfer to carbon electrode surfaces. The results demonstrate that E. coli can be reprogrammed from glycerol fermentation to respiration upon production of the new electron transport chain