Nutrient sensors and their crosstalk

The macronutrients glucose, lipids, and amino acids are the major components that maintain life. The ability of cells to sense and respond to fluctuations in these nutrients is a crucial feature for survival. Nutrient-sensing pathways are thus developed to govern cellular energy and metabolic homeostasis and regulate diverse biological processes. Accordingly, perturbations in these sensing pathways are associated with a wide variety of pathologies, especially metabolic diseases. Molecular sensors are the core within these sensing pathways and have a certain degree of specificity and affinity to sense the intracellular fluctuation of each nutrient either by directly binding to that nutrient or indirectly binding to its surrogate molecules. Once the changes in nutrient levels are detected, sensors trigger signaling cascades to fine-tune cellular processes for energy and metabolic homeostasis, for example, by controlling uptake, de novo synthesis or catabolism of that nutrient. In this review, we summarize the major discoveries on nutrient-sensing pathways and explain how those sensors associated with each pathway respond to intracellular nutrient availability and how these mechanisms control metabolic processes. Later, we further discuss the crosstalk between these sensing pathways for each nutrient, which are intertwined to regulate overall intracellular nutrient/metabolic homeostasis. Metabolism: nutrient sensors and their networksThe ability of cells to sense levels of important nutrients, such as glucose, lipids, and amino acids, is critical for cellular health, and dysregulation such sensing activity can underlie various diseases, especially metabolic diseases. Sensing nutrient levels allows cells to regulate their metabolism and to maintain appropriate nutrient levels by taking up, synthesizing, or breaking down a given nutrient. Jung Min Han at Yonsei University in South Korea and co-workers have reviewed recent discoveries on nutrient sensors and the networks connecting them. Although researchers have identified the sensors of some key molecules, such as glucose and important amino acids such as leucine, how sensing networks interact is poorly understood. Improving our understanding of nutrient sensing will illuminate nutrient supply in both health and disease, and may help to find treatments for metabolic disorders.

Automated summary

The macronutrients glucose, lipids, and amino acids are crucial for maintaining life and their fluctuations are sensed by molecular sensors, triggering signaling cascades to regulate cellular processes for energy and metabolic homeostasis. Perturbations in these nutrient-sensing pathways are associated with various pathologies, especially metabolic diseases. Understanding the networks connecting nutrient sensors can provide insights into nutrient supply in health and disease, and potentially lead to treatments for metabolic disorders.