Interconversion between Anticipatory and Active GID E3 Ubiquitin Ligase Conformations via Metabolically Driven Substrate Receptor Assembly

• Published in: bioRxiv
• Main Authors: Qiao, Shuai, Langlois, Christine R, Chrustowicz, Jakub, Sherpa, Dawafuti, Karayel, Ozge, Hansen, Fynn M, Beier, Viola, Susanne Von Gronau, Bollschweiler, Daniel, Schafer, Tillman, Alpi, Arno F, Mann, Matthias, Jesuraj Rajan Prabu, Schulman, Brenda A
• Format: Paper
• Language: English
• Published: Cold Spring Harbor Cold Spring Harbor Laboratory Press 31.10.2019; Cold Spring Harbor Laboratory
• Edition: 1.1
• Subjects: Electron microscopy; Environmental changes; Gluconeogenesis; Glucose; Homeostasis; Metabolic pathways; Molecular Biology; Ubiquitin; Ubiquitin-protein ligase
• ISSN: 2692-8205; 2692-8205
• DOI: 10.1101/824060

Cells respond to environmental changes by toggling metabolic pathways, preparing for homeostasis, and anticipating future stresses. For example, in Saccharomyces cerevisiae, carbon stress-induced gluconeogenesis is terminated upon glucose availability, a process that involves the multiprotein E3 ligase, GIDSR4, recruiting N-termini and catalyzing ubiquitylation of gluconeogenic enzymes. Here, genetics, biochemistry, and cryo electron microscopy define molecular underpinnings of glucose-induced degradation. Unexpectedly, carbon stress induces an inactive anticipatory complex (GIDAnt), which awaits a glucose-induced substrate receptor to form the active GIDSR4. Meanwhile, other environmental perturbations elicit production of an alternative substrate receptor assembling into a related E3 ligase complex. The intricate structure of GIDAnt enables anticipating and ultimately binding various N-degron targeting (i.e. "N-end rule") substrate receptors, while the GIDSR4 E3 forms a clamp-like structure juxtaposing substrate lysines with the ubiquitylation active site. The data reveal evolutionarily conserved GID complexes as a family of multisubunit E3 ubiquitin ligases responsive to extracellular stimuli.