Intermediary metabolism: An intricate network at the crossroads of cell fate and function

Intermediary metabolism is traditionally viewed as the large, highly integrated network of reactions that provides cells with metabolic energy, reducing power and biosynthetic intermediates. The elucidation of its major pathways and molecular mechanisms of energy transduction occupied some of the brightest scientific minds for almost two centuries. When these goals were achieved, a sense that intermediary metabolism was mostly a solved problem pervaded the broader biochemical community, and the field lost its vitality. However, intermediary metabolism has recently been re-energized by several paradigm-shifting discoveries that challenged its perception as a self-contained system and re-positioned it at the crossroads of all aspects of cell function, from cell growth, proliferation and death to epigenetics and immunity. Emphasis is now increasingly placed on the involvement of metabolic dysfunction in human disease. In this review, we will navigate from the dawn of intermediary metabolism research to present day work on this ever-expanding field.