title: Glucose regulates clathrin adaptors at the trans-Golgi network and endosomes.
abstract: Glucose is a rich source of energy and the raw material for biomass increase. Many eukaryotic cells remodel their physiology in the presence and absence of glucose. The yeast Saccharomyces cerevisiae undergoes changes in transcription, translation, metabolism, and cell polarity in response to glucose availability. Upon glucose starvation, translation initiation and cell polarity are immediately inhibited, and then gradually recover. In this paper, we provide evidence that, as in cell polarity and translation, traffic at the trans-Golgi network (TGN) and endosomes is regulated by glucose via an unknown mechanism that depends on protein kinase A (PKA). Upon glucose withdrawal, clathrin adaptors exhibit a biphasic change in localization: they initially delocalize from the membrane within minutes and later partially recover onto membranes. Additionally, the removal of glucose induces changes in posttranslational modifications of adaptors. Ras and Gpr1 signaling pathways, which converge on PKA, are required for changes in adaptor localization and changes in posttranslational modifications. Acute inhibition of PKA demonstrates that inhibition of PKA prior to glucose withdrawal prevents several adaptor responses to starvation. This study demonstrates that PKA activity prior to glucose starvation primes membrane traffic at the TGN and endosomes in response to glucose starvation.
authors.affiliation: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. qaoh@email.unc.edu
authors.forename: Quyen L
authors.initials: QL
authors.lastname: Aoh
authors.forename: Lee M
authors.initials: LM
authors.lastname: Graves
authors.forename: Mara C
authors.initials: MC
authors.lastname: Duncan
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D011992:Endosomes / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism*; D026901:Membrane Transport Proteins; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D021601:trans-Golgi Network / Q000235:genetics / Q000378:metabolism*
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; C109334:GPR1 protein, S cerevisiae; D026901:Membrane Transport Proteins; D043562:Receptors, G-Protein-Coupled; D029701:Saccharomyces cerevisiae Proteins; D017868:Cyclic AMP-Dependent Protein Kinases; D005947:Glucose