The yeast arrestin-related protein Bul1 is a novel actor of glucose-induced endocytosis

Mol Biol Cell. 2018 May 1;29(9):1012-1020. doi: 10.1091/mbc.E17-07-0466. Epub 2018 Mar 22.

Abstract

Yeast cells have a remarkable ability to adapt to nutritional changes in their environment. During adaptation, nutrient-signaling pathways drive the selective endocytosis of nutrient transporters present at the cell surface. A current challenge is to understand the mechanistic basis of this regulation. Transporter endocytosis is triggered by their ubiquitylation, which involves the ubiquitin ligase Rsp5 and its adaptors of the arrestin-related family (ART). This step is highly regulated by nutrient availability. For instance, the monocarboxylate transporter Jen1 is ubiquitylated, endocytosed, and degraded upon exposure to glucose. The ART protein Rod1 is required for this overall process; yet Rod1 rather controls Jen1 trafficking later in the endocytic pathway and is almost dispensable for Jen1 internalization. Thus, how glucose triggers Jen1 internalization remains unclear. We report that another ART named Bul1, but not its paralogue Bul2, contributes to Jen1 internalization. Bul1 responds to glucose availability, and preferentially acts at the plasma membrane for Jen1 internalization. Thus, multiple ARTs can act sequentially along the endocytic pathway to control transporter homeostasis. Moreover, Bul1 is in charge of Jen1 endocytosis after cycloheximide treatment, suggesting that the functional redundancy of ARTs may be explained by their ability to interact with multiple cargoes in various conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Adaptor Proteins, Signal Transducing / physiology
  • Arrestins / metabolism
  • Cell Membrane / metabolism
  • Endocytosis / physiology*
  • Endosomal Sorting Complexes Required for Transport / metabolism
  • Glucose / metabolism
  • Membrane Proteins / metabolism
  • Membrane Transport Proteins / metabolism
  • Monocarboxylic Acid Transporters / metabolism
  • Protein Transport
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins / physiology*
  • Signal Transduction / physiology
  • Symporters / metabolism
  • Ubiquitin / metabolism
  • Ubiquitin-Protein Ligase Complexes / metabolism
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitin-Protein Ligases / physiology*
  • Ubiquitination / drug effects

Substances

  • Adaptor Proteins, Signal Transducing
  • Arrestins
  • BUL1 protein, S cerevisiae
  • BUL2 protein, S cerevisiae
  • Endosomal Sorting Complexes Required for Transport
  • JEN1 protein, S cerevisiae
  • Membrane Proteins
  • Membrane Transport Proteins
  • Monocarboxylic Acid Transporters
  • Saccharomyces cerevisiae Proteins
  • Symporters
  • Ubiquitin
  • Ubiquitin-Protein Ligase Complexes
  • Ubiquitin-Protein Ligases
  • Glucose