scholarly journals Glucose regulates clathrin adaptors at the trans-Golgi network and endosomes

2011 ◽  
Vol 22 (19) ◽  
pp. 3671-3683 ◽  
Author(s):  
Quyen L. Aoh ◽  
Lee M. Graves ◽  
Mara C. Duncan
Keyword(s):  
Cell Polarity ◽  
Translation Initiation ◽  
Posttranslational Modifications ◽  
Raw Material ◽  
Eukaryotic Cells ◽  
Glucose Starvation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Trans Golgi Network ◽  
Golgi Network ◽  
Biomass Increase

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.

scholarly journals Energy metabolism regulates clathrin adaptors at the trans-Golgi network and endosomes

2013 ◽  
Vol 24 (6) ◽  
pp. 832-847 ◽  
Author(s):  
Quyen L. Aoh ◽  
Chao-wei Hung ◽  
Mara C. Duncan
Keyword(s):  
Energy Metabolism ◽  
Intracellular Signaling ◽  
Phosphatidyl Inositol ◽  
Glucose Starvation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Permeabilized Cells ◽  
Trans Golgi Network ◽  
Golgi Network ◽  
Energy Dependent ◽  
Adp Ribosylation Factor

Glucose is a master regulator of cell behavior in the yeast Saccharomyces cerevisiae. It acts as both a metabolic substrate and a potent regulator of intracellular signaling cascades. Glucose starvation induces the transient delocalization and then partial relocalization of clathrin adaptors at the trans-Golgi network and endosomes. Although these localization responses are known to depend on the protein kinase A (PKA) signaling pathway, the molecular mechanism of this regulation is unknown. Here we demonstrate that PKA and the AMP-regulated kinase regulate adaptor localization through changes in energy metabolism. We show that genetic and chemical manipulation of intracellular ATP levels cause corresponding changes in adaptor localization. In permeabilized cells, exogenous ATP is sufficient to induce adaptor localization. Furthermore, we reveal distinct energy-dependent steps in adaptor localization: a step that requires the ADP-ribosylation factor ARF, an ATP-dependent step that requires the phosphatidyl-inositol-4 kinase Pik1, and third ATP-dependent step for which we provide evidence but for which the mechanism is unknown. We propose that these energy-dependent mechanisms precisely synchronize membrane traffic with overall proliferation rates and contribute a crucial aspect of energy conservation during acute glucose starvation.

scholarly journals Plasma membrane to vacuole traffic induced by glucose starvation requires Gga2‐dependent sorting at the trans ‐Golgi network

2020 ◽  
Vol 112 (11) ◽  
pp. 349-367
Author(s):  
Destiney Buelto ◽  
Chao‐Wei Hung ◽  
Quyen L. Aoh ◽  
Sagar Lahiri ◽  
Mara C. Duncan
Keyword(s):  
Plasma Membrane ◽  
Glucose Starvation ◽  
Trans Golgi Network ◽  
Golgi Network

scholarly journals Segregation of sphingolipids and sterols during formation of secretory vesicles at the trans-Golgi network

2009 ◽  
Vol 185 (4) ◽  
pp. 601-612 ◽  
Author(s):  
Robin W. Klemm ◽  
Christer S. Ejsing ◽  
Michal A. Surma ◽  
Hermann-Josef Kaiser ◽  
Mathias J. Gerl ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Secretory Pathway ◽  
Membrane Lipids ◽  
Secretory Vesicles ◽  
Shotgun Lipidomics ◽  
Yeast Saccharomyces Cerevisiae ◽  
Trans Golgi Network ◽  
Sorting Station ◽  
Golgi Network ◽  
First Time

The trans-Golgi network (TGN) is the major sorting station in the secretory pathway of all eukaryotic cells. How the TGN sorts proteins and lipids to generate the enrichment of sphingolipids and sterols at the plasma membrane is poorly understood. To address this fundamental question in membrane trafficking, we devised an immunoisolation procedure for specific recovery of post-Golgi secretory vesicles transporting a transmembrane raft protein from the TGN to the cell surface in the yeast Saccharomyces cerevisiae. Using a novel quantitative shotgun lipidomics approach, we could demonstrate that TGN sorting selectively enriched ergosterol and sphingolipid species in the immunoisolated secretory vesicles. This finding, for the first time, indicates that the TGN exhibits the capacity to sort membrane lipids. Furthermore, the observation that the immunoisolated vesicles exhibited a higher membrane order than the late Golgi membrane, as measured by C-Laurdan spectrophotometry, strongly suggests that lipid rafts play a role in the TGN-sorting machinery.

scholarly journals PAR3 and aPKC regulate Golgi organization through CLASP2 phosphorylation to generate cell polarity

2015 ◽  
Vol 26 (4) ◽  
pp. 751-761 ◽  
Author(s):  
Toshinori Matsui ◽  
Takashi Watanabe ◽  
Kenji Matsuzawa ◽  
Mai Kakeno ◽  
Nobumasa Okumura ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Golgi Apparatus ◽  
Cell Polarity ◽  
Cross Talk ◽  
Cell Polarization ◽  
Trans Golgi Network ◽  
Golgi Ribbon ◽  
Golgi Network ◽  
Golgi Organization

The organization of the Golgi apparatus is essential for cell polarization and its maintenance. The polarity regulator PAR complex (PAR3, PAR6, and aPKC) plays critical roles in several processes of cell polarization. However, how the PAR complex participates in regulating the organization of the Golgi remains largely unknown. Here we demonstrate the functional cross-talk of the PAR complex with CLASP2, which is a microtubule plus-end–tracking protein and is involved in organizing the Golgi ribbon. CLASP2 directly interacted with PAR3 and was phosphorylated by aPKC. In epithelial cells, knockdown of either PAR3 or aPKC induced the aberrant accumulation of CLASP2 at the trans-Golgi network (TGN) concomitantly with disruption of the Golgi ribbon organization. The expression of a CLASP2 mutant that inhibited the PAR3-CLASP2 interaction disrupted the organization of the Golgi ribbon. CLASP2 is known to localize to the TGN through its interaction with the TGN protein GCC185. This interaction was inhibited by the aPKC-mediated phosphorylation of CLASP2. Furthermore, the nonphosphorylatable mutant enhanced the colocalization of CLASP2 with GCC185, thereby perturbing the Golgi organization. On the basis of these observations, we propose that PAR3 and aPKC control the organization of the Golgi through CLASP2 phosphorylation.

scholarly journals Visualization of secretory cargo transport within the Golgi apparatus

2019 ◽  
Vol 218 (5) ◽  
pp. 1602-1618 ◽  
Author(s):  
Kazuo Kurokawa ◽  
Hiroko Osakada ◽  
Tomoko Kojidani ◽  
Miho Waga ◽  
Yasuyuki Suda ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Golgi Apparatus ◽  
Yeast Saccharomyces Cerevisiae ◽  
Trans Golgi Network ◽  
Golgi Cisterna ◽  
Cargo Transport ◽  
Golgi Network ◽  
Interesting Behavior

To describe trafficking of secretory cargo within the Golgi apparatus, the cisternal maturation model predicts that Golgi cisternae change their properties from cis to trans while cargo remains in the cisternae. Cisternal change has been demonstrated in living yeast Saccharomyces cerevisiae; however, the behavior of cargo has yet to be examined directly. In this study, we conducted simultaneous three-color and four-dimensional visualization of secretory transmembrane cargo together with early and late Golgi resident proteins. We show that cargo stays in a Golgi cisterna during maturation from cis-Golgi to trans-Golgi and further to the trans-Golgi network (TGN), which involves dynamic mixing and segregation of two zones of the earlier and later Golgi resident proteins. The location of cargo changes from the early to the late zone within the cisterna during the progression of maturation. In addition, cargo shows an interesting behavior during the maturation to the TGN. After most cargo has reached the TGN zone, a small amount of cargo frequently reappears in the earlier zone.

Post-Golgi biosynthetic trafficking

1997 ◽  
Vol 110 (24) ◽  
pp. 3001-3009 ◽  
Author(s):  
P. Keller ◽  
K. Simons
Keyword(s):  
Cell Surface ◽  
Golgi Complex ◽  
Cell Types ◽  
Bulk Flow ◽  
Eukaryotic Cells ◽  
Flow Process ◽  
Trans Golgi Network ◽  
Golgi Network ◽  
Different Cell Types

Eukaryotic cells have developed complex machineries to distribute proteins and lipids from the Golgi complex. Contrary to what has originally been postulated, delivery of proteins to the cell surface is not a simple bulk flow process but involves sorting into distinct pathways from the trans-Golgi network. Here we describe the various routes emerging from the trans-Golgi network in different cell types, and we discuss the mechanisms that mediate sorting into these pathways. While much remains to be learned about these sorting mechanisms, it is apparent that a number of pathways previously believed to be restricted to certain cell types might be used more commonly.

scholarly journals Vps10p Transport from the trans-Golgi Network to the Endosome Is Mediated by Clathrin-coated Vesicles

2001 ◽  
Vol 12 (2) ◽  
pp. 475-485 ◽  
Author(s):  
Olivier Deloche ◽  
Bonny G. Yeung ◽  
Gregory S. Payne ◽  
Randy Schekman
Keyword(s):  
Large Subunit ◽  
Adaptor Protein ◽  
Coated Vesicles ◽  
Carboxypeptidase Y ◽  
Yeast Saccharomyces Cerevisiae ◽  
Trans Golgi Network ◽  
Protein Receptor ◽  
Vacuolar Protein ◽  
Golgi Network

A native immunoisolation procedure has been used to investigate the role of clathrin-coated vesicles (CCVs) in the transport of vacuolar proteins between the trans-Golgi network (TGN) and the prevacuolar/endosome compartments in the yeast Saccharomyces cerevisiae. We find that Apl2p, one large subunit of the adaptor protein-1 complex, and Vps10p, the carboxypeptidase Y vacuolar protein receptor, are associated with clathrin molecules. Vps10p packaging in CCVs is reduced in pep12Δ andvps34Δ, two mutants that block Vps10p transport from the TGN to the endosome. However, Vps10p sorting is independent of Apl2p. Interestingly, a Vps10CtΔp mutant lacking its C-terminal cytoplasmic domain, the portion of the receptor responsible for carboxypeptidase Y sorting, is also coimmunoprecipitated with clathrin. Our results suggest that CCVs mediate Vps10p transport from the TGN to the endosome independent of direct interactions between Vps10p and clathrin coats. The Vps10p C-terminal domain appears to play a principal role in retrieval of Vps10p from the prevacuolar compartment rather than in sorting from the TGN.

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