scholarly journals Transport Vesicle Tethering at the Trans Golgi Network: Coiled Coil Proteins in Action

2016 ◽  
Vol 4 ◽  
Author(s):  
Pak-yan P. Cheung ◽  
Suzanne R. Pfeffer
Keyword(s):  
Coiled Coil ◽  
Vesicle Tethering ◽  
Trans Golgi Network ◽  
Transport Vesicle ◽  
Golgi Network

scholarly journals GCC185 plays independent roles in Golgi structure maintenance and AP-1–mediated vesicle tethering

2011 ◽  
Vol 194 (5) ◽  
pp. 779-787 ◽  
Author(s):  
Frank C. Brown ◽  
Carmel H. Schindelhaim ◽  
Suzanne R. Pfeffer
Keyword(s):  
Coiled Coil ◽  
Retrograde Transport ◽  
Vesicle Tethering ◽  
Transport Vesicles ◽  
Late Endosomes ◽  
Transport Vesicle ◽  
Golgi Structure ◽  
Clathrin Adaptor ◽  
Golgi Network

GCC185 is a long coiled-coil protein localized to the trans-Golgi network (TGN) that functions in maintaining Golgi structure and tethering mannose 6-phosphate receptor (MPR)–containing transport vesicles en route to the Golgi. We report the identification of two distinct domains of GCC185 needed either for Golgi structure maintenance or transport vesicle tethering, demonstrating the independence of these two functions. The domain needed for vesicle tethering binds to the clathrin adaptor AP-1, and cells depleted of GCC185 accumulate MPRs in transport vesicles that are AP-1 decorated. This study supports a previously proposed role of AP-1 in retrograde transport of MPRs from late endosomes to the Golgi and indicates that docking may involve the interaction of vesicle-associated AP-1 protein with the TGN-associated tethering protein GCC185.

scholarly journals A Novel Rab9 Effector Required for Endosome-to-TGN Transport

1997 ◽  
Vol 138 (2) ◽  
pp. 283-290 ◽  
Author(s):  
Elva Díaz ◽  
Frauke Schimmöller ◽  
Suzanne R. Pfeffer
Keyword(s):  
Active Form ◽  
Sucrose Density Gradient ◽  
Vesicle Docking ◽  
Trans Golgi Network ◽  
Yeast Two Hybrid System ◽  
Transport Assay ◽  
Transport Vesicle ◽  
Mannose 6 Phosphate ◽  
Golgi Network

Rab9 GTPase is required for the transport of mannose 6-phosphate receptors from endosomes to the trans-Golgi network in living cells, and in an in vitro system that reconstitutes this process. We have used the yeast two-hybrid system to identify proteins that interact preferentially with the active form of Rab9. We report here the discovery of a 40-kD protein (p40) that binds Rab9–GTP with roughly fourfold preference to Rab9–GDP. p40 does not interact with Rab7 or K-Ras; it also fails to bind Rab9 when it is bound to GDI. The protein is found in cytosol, yet a significant fraction (∼30%) is associated with cellular membranes. Upon sucrose density gradient flotation, membrane- associated p40 cofractionates with endosomes containing mannose 6-phosphate receptors and the Rab9 GTPase. p40 is a very potent transport factor in that the pure, recombinant protein can stimulate, significantly, an in vitro transport assay that measures transport of mannose 6-phosphate receptors from endosomes to the trans-Golgi network. The functional importance of p40 is confirmed by the finding that anti-p40 antibodies inhibit in vitro transport. Finally, p40 shows synergy with Rab9 in terms of its ability to stimulate mannose 6-phosphate receptor transport. These data are consistent with a model in which p40 and Rab9 act together to drive the process of transport vesicle docking.

Expansion of the trans-Golgi network following activated collagen secretion is supported by a coiled–coil microtubule-bundling protein, p180, on the ER

2010 ◽  
Vol 316 (3) ◽  
pp. 329-340 ◽  
Author(s):  
Tomonori Ueno ◽  
Keiko Kaneko ◽  
Harutaka Katano ◽  
Yuko Sato ◽  
Ralph Mazitschek ◽  
...  
Keyword(s):  
Coiled Coil ◽  
Trans Golgi Network ◽  
Collagen Secretion ◽  
Golgi Network

scholarly journals A Family of Proteins with γ-Adaptin and Vhs Domains That Facilitate Trafficking between the Trans-Golgi Network and the Vacuole/Lysosome

2000 ◽  
Vol 149 (1) ◽  
pp. 67-80 ◽  
Author(s):  
Jennifer Hirst ◽  
Winnie W.Y. Lui ◽  
Nicholas A. Bright ◽  
Nicholas Totty ◽  
Matthew N.J. Seaman ◽  
...  
Keyword(s):  
Coiled Coil ◽  
Coated Vesicles ◽  
Carboxypeptidase Y ◽  
Golgi Stack ◽  
Trans Golgi Network ◽  
Terminal Domain ◽  
Vhs Domain ◽  
Golgi Network ◽  
Terminal Domains

We have cloned and characterized members of a novel family of proteins, the GGAs. These proteins contain an NH2-terminal VHS domain, one or two coiled-coil domains, and a COOH-terminal domain homologous to the COOH-terminal “ear” domain of γ-adaptin. However, unlike γ-adaptin, the GGAs are not associated with clathrin-coated vesicles or with any of the components of the AP-1 complex. GGA1 and GGA2 are also not associated with each other, although they colocalize on perinuclear membranes. Immunogold EM shows that these membranes correspond to trans elements of the Golgi stack and the TGN. GST pulldown experiments indicate that the GGA COOH-terminal domains bind to a subset of the proteins that bind to the γ-adaptin COOH-terminal domain. In yeast there are two GGA genes. Deleting both of these genes results in missorting of the vacuolar enzyme carboxypeptidase Y, and the cells also have a defective vacuolar morphology phenotype. These results indicate that the function of the GGAs is to facilitate the trafficking of proteins between the TGN and the vacuole, or its mammalian equivalent, the lysosome.

scholarly journals ARFRP1 functions upstream of ARL1 and ARL5 to coordinate recruitment of distinct tethering factors to the trans-Golgi network

2019 ◽  
Vol 218 (11) ◽  
pp. 3681-3696 ◽  
Author(s):  
Morié Ishida ◽  
Juan S. Bonifacino
Keyword(s):  
Coiled Coil ◽  
Concerted Action ◽  
Long Distance ◽  
Master Regulator ◽  
Trans Golgi Network ◽  
Golgi Network

SNARE-mediated fusion of endosome-derived transport carriers with the trans-Golgi network (TGN) depends on the concerted action of two types of tethering factors: long coiled-coil tethers of the golgin family, and the heterotetrameric complex GARP. Whereas the golgins mediate long-distance capture of the carriers, GARP promotes assembly of the SNAREs. It remains to be determined, however, how the functions of these tethering factors are coordinated. Herein we report that the ARF-like (ARL) GTPase ARFRP1 functions upstream of two other ARL GTPases, ARL1 and ARL5, which in turn recruit golgins and GARP, respectively, to the TGN. We also show that this mechanism is essential for the delivery of retrograde cargos to the TGN. Our findings thus demonstrate that ARFRP1 is a master regulator of retrograde-carrier tethering to the TGN. The coordinated recruitment of distinct tethering factors by a bifurcated GTPase cascade may be paradigmatic of other vesicular fusion events within the cell.

scholarly journals The trans-Golgi network GRIP-domain proteins form α-helical homodimers

2005 ◽  
Vol 388 (3) ◽  
pp. 835-841 ◽  
Author(s):  
Michael R. LUKE ◽  
Fiona HOUGHTON ◽  
Matthew A. PERUGINI ◽  
Paul A. GLEESON
Keyword(s):  
Protein Interactions ◽  
Coiled Coil ◽  
Helical Structure ◽  
Cd Spectroscopy ◽  
Protein Protein Interactions ◽  
Yeast Two Hybrid ◽  
Trans Golgi Network ◽  
Heptad Repeats ◽  
Golgi Network ◽  
Two Hybrid

A recently described family of TGN (trans-Golgi network) proteins, all of which contain a GRIP domain targeting sequence, has been proposed to play a role in membrane transport. On the basis of the high content of heptad repeats, GRIP domain proteins are predicted to contain extensive coiled-coil regions that have the potential to mediate protein–protein interactions. Four mammalian GRIP domain proteins have been identified which are targeted to the TGN through their GRIP domains, namely p230, golgin-97, GCC88 and GCC185. In the present study, we have investigated the ability of the four mammalian GRIP domain proteins to interact. Using a combination of immunoprecipitation experiments of epitope-tagged GRIP domain proteins, cross-linking experiments and yeast two-hybrid interactions, we have established that the GRIP proteins can self-associate to form homodimers exclusively. Two-hybrid analysis indicated that the N- and C-terminal fragments of GCC88 can interact with themselves but not with each other, suggesting that the GRIP domain proteins form parallel coiled-coil dimers. Analysis of purified recombinant golgin-97 by CD spectroscopy indicated a 67% α-helical structure, consistent with a high content of coiled-coil sequences. These results support a model for GRIP domain proteins as extended rod-like homodimeric molecules. The formation of homodimers, but not heterodimers, indicates that each of the four mammalian TGN golgins has the potential to function independently.

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