Coordination of microbial metabolism

Abstract

Beyond fuelling cellular activities with building blocks and energy, metabolism also integrates environmental conditions into intracellular signals. The underlying regulatory network is complex and multifaceted: it ranges from slow interactions, such as changing gene expression, to rapid ones, such as the modulation of protein activity via post-translational modification or the allosteric binding of small molecules. In this Review, we outline the coordination of common metabolic tasks, including nutrient uptake, central metabolism, the generation of energy, the supply of amino acids and protein synthesis. Increasingly, a set of key metabolites is recognized to control individual regulatory circuits, which carry out specific functions of information input and regulatory output. Such a modular view of microbial metabolism facilitates an intuitive understanding of the molecular mechanisms that underlie cellular decision making.

Inter-comparison of the potentially active prokaryotic communities in the halocline sediments of Mediterranean deep-sea hypersaline basins

“…Within microbial communities, responses to environmental variations occur first at the cellular level, and if these conditions persist long enough and are intense enough, then responses can be monitored at the population level. Moreover, although prokaryotes are characterized by tremendous observed but yetlargely-undetermined structural diversity, this results in overlapping metabolic traits, especially regarding core metabolism even between highly divergent species (Chubukov et al 2014). Since DNA is preserved far longer in marine sediments in comparison to RNA (e.g.…”

Metabolic sensor governing bacterial virulence in Staphylococcus aureus

“…For example, in vertebrate hosts one of the first lines of defense against S. aureus infection is withholding iron to prevent the growth of S. aureus; therefore S. aureus has evolved highly efficient nutrient-retrieval strategies to counteract this nutritional deprivation (11,17,18). However, although it is well known that nutrients modulate intracellular metabolic status, as reflected by the concentration of key metabolic intermediates (19)(20)(21)(22), the links between the metabolic intermediates and the expression of S. aureus virulence factors remain largely unknown (6).…”

Galactose metabolic genes in yeast respond to a ratio of galactose and glucose

“…In an environment that contains a mixture of sugars, such as glucose and galactose, microbial cells regulate their response according to a carbon hierarchy mediated by catabolite repression. Galactose metabolic genes (GAL genes) are induced to a significant degree only after glucose-based catabolite repression is relieved, resulting in a lag in growth at the point of glucose exhaustion while GAL pathway proteins are produced (1)(2)(3)(4)(5)(6). Recent studies of sugar integration in bacteria (7,8) suggested that in these organisms the combinatorial response results from the multiplication of individual responses to different sugars.…”

“…The response of Saccharomyces cerevisiae to galactose is one of the best-studied eukaryotic signaling pathways (1,(4)(5)(6)(9)(10)(11)(12). The GAL response has become a canonical example for combinatorial signal integration based on a genetic switch (10)(11)(12)(13).…”