Glycolytic Enzyme Coalesce in G bodies Under Hypoxic Stress

Glycolysis is upregulated in cells under specific conditions, such as hypoxia and high energy demand, to achieve the metabolic requirements for continued cell proliferation. However, the mechanism of this increased glycolytic rate remains poorly understood. In the budding yeast Saccharomyces cerevisiae, we discovered that hypoxia induces concentration of many glycolytic enzymes, including the Pfk2p subunit of the ratelimiting enzyme, phosphofructokinase, into a single, non-membrane-bound granule that we define as the "glycolytic body" or "G body". Pfk2p localization to G bodies depends on its N-terminal, intrinsically disordered region. In order to identify factors important for G body formation, we conducted a yeast kinome screen and identified the AMP kinase ortholog, Snf1p, to be required for the localization of multiple glycolytic enzymes to G bodies. Further, proteomic analyses of purified G bodies identified a core set of resident factors, many of which are essential for G body integrity. Cells incapable of forming G bodies in hypoxic conditions display abnormal cell division and produce inviable daughter cells. Conversely, cells that form G bodies show increased glucose consumption and decreased levels of glycolytic intermediates. Importantly, G bodies also form in human, hepatocarcinoma cells upon hypoxic stress. Together, our results suggest that G body formation is a conserved, adaptive response to increase glycolytic output during hypoxia or tumorigenesis.