title: Mitotic Checkpoint Regulators Control Insulin Signaling and Metabolic Homeostasis.
abstract: Insulin signaling regulates many facets of animal physiology. Its dysregulation causes diabetes and other metabolic disorders. The spindle checkpoint proteins MAD2 and BUBR1 prevent precocious chromosome segregation and suppress aneuploidy. The MAD2 inhibitory protein p31(comet) promotes checkpoint inactivation and timely chromosome segregation. Here, we show that whole-body p31(comet) knockout mice die soon after birth and have reduced hepatic glycogen. Liver-specific ablation of p31(comet) causes insulin resistance, hyperinsulinemia, glucose intolerance, and hyperglycemia and diminishes the plasma membrane localization of the insulin receptor (IR) in hepatocytes. MAD2 directly binds to IR and facilitates BUBR1-dependent recruitment of the clathrin adaptor AP2 to IR. p31(comet) blocks the MAD2-BUBR1 interaction and prevents spontaneous clathrin-mediated IR endocytosis. BUBR1 deficiency enhances insulin sensitivity in mice. BUBR1 depletion in hepatocytes or the expression of MAD2-binding-deficient IR suppresses the metabolic phenotypes of p31(comet) ablation. Our findings establish a major IR regulatory mechanism and link guardians of chromosome stability to nutrient metabolism.
authors.affiliation: Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390, USA.
authors.forename: Eunhee
authors.initials: E
authors.lastname: Choi
authors.affiliation: Bioinformatics Core, Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390, USA.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Bioinformatics Core, Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390, USA.
authors.forename: Chao
authors.initials: C
authors.lastname: Xing
authors.affiliation: Howard Hughes Medical Institute, Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390, USA. Electronic address: hongtao.yu@utsouthwestern.edu.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Yu
mesh_terms: D033962:Adaptor Protein Complex 2 / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing; D000782:Aneuploidy; D000818:Animals; D059447:Cell Cycle Checkpoints; D018797:Cell Cycle Proteins / Q000378:metabolism; D002478:Cells, Cultured; D020090:Chromosome Segregation; D002966:Clathrin / Q000378:metabolism; D004705:Endocytosis; D056945:Hep G2 Cells; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D008099:Liver / Q000378:metabolism; D064246:Mad2 Proteins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008938:Mitosis; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011972:Receptor, Insulin / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D033962:Adaptor Protein Complex 2; D048868:Adaptor Proteins, Signal Transducing; C584278:Bub1b protein, mouse; D018797:Cell Cycle Proteins; D002966:Clathrin; D007328:Insulin; D064246:Mad2 Proteins; C577698:Mad2l1 protein, mouse; C000612540:Mad2l1bp protein, mouse; D009687:Nuclear Proteins; D011972:Receptor, Insulin; D017346:Protein Serine-Threonine Kinases