Biology subjects

Toh, M.

Publications and source records attributed to Toh, M..

2 recordsLinked to original sources

bioRxiv2021

A Creb3-Like Transcription Factor Coordinates ER Function uponFood Intake to Regulate Lipid Metabolism

Ingestion of nutrients elicits essential physiological responses, including absorption, digestion, cessation of feeding and nutrient storage. The endoplasmic reticulum (ER) is central to this nutritional homeostasis, since it regulates intracellular organelle function, drives intercellular communication and promotes metabolite distribution. We identified the Drosophila Creb3L-family transcription factor, CrebA, as the key metabolic regulator of ER function, thereby affecting lipid metabolism and feeding behavior. In response to feeding, CrebA activity is rapidly and transiently activated. CrebA directly drives the expression of the ER protein sorting machinery. We demonstrate that CrebA levels regulate lipid metabolism through lipoprotein secretion into the hemolymph and suppress feeding behavior. Further, CrebA mouse homologs are also upregulated in the liver following feeding and drive the transcriptional activation of ER protein sorting machinery genes in mammals. Our results reveal an evolutionarily conserved transcription switch which is turned on in response to food ingestion and orchestrates a negative feedback loop that promotes satiety by regulating ER function and protein secretion.

cell biology↗

bioRxiv2020

A Streptomyces venezuelae Cell-Free Toolkit for Synthetic Biology

Prokaryotic cell-free coupled transcription-translation (TX-TL) systems are emerging as a powerful tool to examine natural product biosynthetic pathways in a test-tube. The key advantages of this approach are the reduced experimental timescales and controlled reaction conditions. In order to realise this potential, specialised cell-free systems in organisms enriched for biosynthetic gene clusters, with strong protein production and well-characterised synthetic biology tools, is essential. The Streptomyces genus is a major source of natural products. To study enzymes and pathways from Streptomyces, we originally developed a homologous Streptomyces cell-free system to provide a native protein folding environment, a high G+C (%) tRNA pool and an active background metabolism. However, our initial yields were low (36 g/mL) and showed a high level of batch-to-batch variation. Here, we present an updated high-yield and robust Streptomyces TX-TL protocol, reaching up to yields of 266 g/mL of expressed recombinant protein. To complement this, we rapidly characterise a range of DNA parts with different reporters, express high G+C (%) biosynthetic genes and demonstrate an initial proof of concept for combined transcription, translation and biosynthesis of Streptomyces metabolic pathways in a single one-pot reaction.

synthetic biology↗