PROTEIN SORTING AND CLATHRIN-COATED VESICLE FORMATION IN THE TRANS-GOLGI NETWORK

1996 ◽  
Vol 24 (4) ◽  
pp. 586S-586S
Author(s):  
Bernard HOFLACK
Keyword(s):  
Protein Sorting ◽  
Coated Vesicle ◽  
Vesicle Formation ◽  
Trans Golgi Network ◽  
Golgi Network

scholarly journals Actin dynamics coupled to clathrin-coated vesicle formation at the trans-Golgi network

2004 ◽  
Vol 165 (6) ◽  
pp. 781-788 ◽  
Author(s):  
Sebastien Carreno ◽  
Åsa E. Engqvist-Goldstein ◽  
Claire X. Zhang ◽  
Kent L. McDonald ◽  
David G. Drubin
Keyword(s):  
Time Lapse ◽  
Actin Dynamics ◽  
Coated Vesicle ◽  
Cell Cortex ◽  
Actin Assembly ◽  
Trans Golgi Network ◽  
Lysosome Biogenesis ◽  
Diverse Species ◽  
Golgi Network ◽  
Golgi Organization

In diverse species, actin assembly facilitates clathrin-coated vesicle (CCV) formation during endocytosis. This role might be an adaptation specific to the unique environment at the cell cortex, or it might be fundamental, facilitating CCV formation on different membranes. Proteins of the Sla2p/Hip1R family bind to actin and clathrin at endocytic sites in yeast and mammals. We hypothesized that Hip1R might also coordinate actin assembly with clathrin budding at the trans-Golgi network (TGN). Using deconvolution and time-lapse microscopy, we showed that Hip1R is present on CCVs emerging from the TGN. These vesicles contain the mannose 6-phosphate receptor involved in targeting proteins to the lysosome, and the actin nucleating Arp2/3 complex. Silencing of Hip1R expression by RNAi resulted in disruption of Golgi organization and accumulation of F-actin structures associated with CCVs on the TGN. Hip1R silencing and actin poisons slowed cathepsin D exit from the TGN. These studies establish roles for Hip1R and actin in CCV budding from the TGN for lysosome biogenesis.

scholarly journals Ride the wave: Retrograde trafficking becomes Ca2+ dependent with BAIAP3

2017 ◽  
Vol 216 (7) ◽  
pp. 1887-1889 ◽  
Author(s):  
Jakob B. Sørensen
Keyword(s):  
Angiogenesis Inhibitor ◽  
Secretory Vesicle ◽  
Vesicle Formation ◽  
Retrograde Trafficking ◽  
Trans Golgi Network ◽  
Cell Biol ◽  
Golgi Network

The functions of four of the five proteins in the mammalian uncoordinated-13 (Munc13) family have been identified as priming factors in SNARE-dependent exocytosis. In this issue, Zhang et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201702099) show that the fifth member, BAIAP3 (brain-specific angiogenesis inhibitor I–associated protein 3), acts in retrograde trafficking by returning secretory vesicle material to the trans-Golgi network. In its absence, secretory vesicle formation is impaired, leading to accumulation of immature vesicles, or lysosomal vesicle degradation.

scholarly journals Adaptor and Clathrin Exchange at the Plasma Membrane andtrans-Golgi Network

2003 ◽  
Vol 14 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Xufeng Wu ◽  
Xiaohong Zhao ◽  
Rosa Puertollano ◽  
Juan S. Bonifacino ◽  
Evan Eisenberg ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Fluorescence Recovery After Photobleaching ◽  
Fluorescence Recovery ◽  
Coated Vesicle ◽  
Coated Pits ◽  
Trans Golgi Network ◽  
Rapid Exchange ◽  
Dynamic Structures ◽  
Golgi Network ◽  
Network Exchange

We previously demonstrated, using fluorescence recovery after photobleaching, that clathrin in clathrin-coated pits at the plasma membrane exchanges with free clathrin in the cytosol, suggesting that clathrin-coated pits are dynamic structures. We now investigated whether clathrin at the trans-Golgi network as well as the clathrin adaptors AP2 and AP1 in clathrin-coated pits at the plasma membrane and trans-Golgi network, respectively, also exchange with free proteins in the cytosol. We found that when the budding of clathrin-coated vesicle is blocked without significantly affecting the structure of clathrin-coated pits, both clathrin and AP2 at the plasma membrane and clathrin and AP1 at thetrans-Golgi network exchange rapidly with free proteins in the cytosol. In contrast, when budding of clathrin-coated vesicles was blocked at the plasma membrane or trans-Golgi network by hypertonic sucrose or K+ depletion, conditions that markedly affect the structure of clathrin-coated pits, clathrin exchange was blocked but AP2 at the plasma membrane and both AP1 and the GGA1 adaptor at the trans-Golgi network continue to rapidly exchange. We conclude that clathrin-coated pits are dynamic structures with rapid exchange of both clathrin and adaptors and that adaptors are able to exchange independently of clathrin when clathrin exchange is blocked.

GGA proteins: new players in the sorting game

2001 ◽  
Vol 114 (19) ◽  
pp. 3413-3418 ◽  
Author(s):  
Annette L. Boman
Keyword(s):  
Membrane Trafficking ◽  
Sequence Homology ◽  
Mammalian Cells ◽  
Gene Knockout ◽  
Protein Domains ◽  
Vesicle Formation ◽  
Trans Golgi Network ◽  
And Function ◽  
Golgi Network ◽  
Cargo Sorting

The GGA proteins are a novel family of proteins that were discovered nearly simultaneously by several labs studying very different aspects of membrane trafficking. Since then, several studies have described the GGA proteins and their functions in yeast and mammalian cells. Four protein domains are present in all GGA proteins, as defined by sequence homology and function. These different domains interact directly with ARF proteins, cargo and clathrin. Alteration of the levels of GGA proteins by gene knockout or overexpression affects specific trafficking events between the trans-Golgi network and endosomes. These data suggest that GGAs function as ARF-dependent, monomeric clathrin adaptors to facilitate cargo sorting and vesicle formation at the trans-Golgi network.

scholarly journals Influenza M2 Proton Channel Activity Selectively Inhibits Trans-Golgi Network Release of Apical Membrane and Secreted Proteins in Polarized Madin-Darby Canine Kidney Cells

2000 ◽  
Vol 148 (3) ◽  
pp. 495-504 ◽  
Author(s):  
Jennifer R. Henkel ◽  
Gregory A. Gibson ◽  
Paul A. Poland ◽  
Mark A. Ellis ◽  
Rebecca P. Hughey ◽  
...  
Keyword(s):  
Ion Channel ◽  
Apical Membrane ◽  
Mdck Cells ◽  
Protein Sorting ◽  
Madin Darby Canine Kidney ◽  
Trans Golgi Network ◽  
Golgi Network ◽  
Kinetics Of ◽  
Darby Canine Kidney ◽  
Canine Kidney

The function of acidification in protein sorting along the biosynthetic pathway has been difficult to elucidate, in part because reagents used to alter organelle pH affect all acidified compartments and are poorly reversible. We have used a novel approach to examine the role of acidification in protein sorting in polarized Madin-Darby canine kidney (MDCK) cells. We expressed the influenza virus M2 protein, an acid-activated ion channel that equilibrates lumenal and cytosolic pH, in polarized MDCK cells and examined the consequences on the targeting and delivery of apical and basolateral proteins. M2 activity affects the pH of only a subset of acidified organelles, and its activity can be rapidly reversed using ion channel blockers (Henkel, J.R., G. Apodaca, Y. Altschuler, S. Hardy, and O.A. Weisz. 1998. Mol. Biol. Cell. 8:2477–2490; Henkel, J.R., J.L. Popovich, G.A. Gibson, S.C. Watkins, and O.A. Weisz. 1999. J. Biol. Chem. 274:9854–9860). M2 expression significantly decreased the kinetics of cell surface delivery of the apical membrane protein influenza hemagglutinin, but not of the basolaterally delivered polymeric immunoglobulin receptor. Similarly, the kinetics of apical secretion of a soluble form of γ-glutamyltranspeptidase were reduced with no effect on the basolaterally secreted fraction. Interestingly, M2 activity had no effect on the rate of secretion of a nonglycosylated protein (human growth hormone [hGH]) that was secreted equally from both surfaces. However, M2 slowed apical secretion of a glycosylated mutant of hGH that was secreted predominantly apically. Our results suggest a role for acidic trans-Golgi network pH in signal-mediated loading of apical cargo into forming vesicles.

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