Polyphosphate is a primordial chaperone.

Composed of up to 1,000 phospho-anhydride bond-linked phosphate monomers, inorganic polyphosphate (polyP) is one of the most ancient, conserved, and enigmatic molecules in biology. Here we demonstrate that polyP functions as a hitherto unrecognized chaperone. We show that polyP stabilizes proteins in vivo, diminishes the need for other chaperone systems to survive proteotoxic stress conditions, and protects a wide variety of proteins against stress-induced unfolding and aggregation. In vitro studies reveal that polyP has protein-like chaperone qualities, binds to unfolding proteins with high affinity in an ATP-independent manner, and supports their productive refolding once nonstress conditions are restored. Our results uncover a universally important function for polyP and suggest that these long chains of inorganic phosphate may have served as one of nature's first chaperones, a role that continues to the present day.

Temperature regulation as a tool to program synthetic microbial community composition.

Engineering of synthetic microbial communities is emerging as a powerful new paradigm for performing various industrially, medically, and environmentally important processes. To reach the fullest potential, however, this approach requires further development in many aspects, a key one being regulating the community composition. Here we leverage well-established mechanisms in ecology which govern the relative abundance of multispecies ecosystems and develop a new tool for programming the composition of synthetic microbial communities. Using a simple model system consisting of two microorganisms Escherichia coli and Pseudomonas putida, which occupy different but partially overlapping thermal niches, we demonstrated that temperature regulation could be used to enable coexistence and program the community composition. We first investigated a constant temperature regime and showed that different temperatures led to different community compositions. Next, we invented a new cycling temperature regime and showed that it can dynamically tune the microbial community, achieving a wide range of compositions depending on parameters that are readily manipulatable. Our work provides conclusive proof of concept that temperature regulation is a versatile and powerful tool capable of programming compositions of synthetic microbial communities.

Meeting report: SMART timing--principles of single molecule techniques course at the University of Michigan 2014.

Four days after the announcement of the 2014 Nobel Prize in Chemistry for "the development of super-resolved fluorescence microscopy" based on single molecule detection, the Single Molecule Analysis in Real-Time (SMART) Center at the University of Michigan hosted a "Principles of Single Molecule Techniques 2014" course. Through a combination of plenary lectures and an Open House at the SMART Center, the course took a snapshot of a technology with an especially broad and rapidly expanding range of applications in the biomedical and materials sciences. Highlighting the continued rapid emergence of technical and scientific advances, the course underscored just how brightly the future of the single molecule field shines.