Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2016 Mar 15:4:18.
doi: 10.3389/fcell.2016.00018. eCollection 2016.

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

Pak-Yan P Cheung  1 , Suzanne R Pfeffer  1
Affiliations
Review

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

Pak-Yan P Cheung et al. Front Cell Dev Biol. .

Abstract

The Golgi complex is decorated with so-called Golgin proteins that share a common feature: a large proportion of their amino acid sequences are predicted to form coiled-coil structures. The possible presence of extensive coiled coils implies that these proteins are highly elongated molecules that can extend a significant distance from the Golgi surface. This property would help them to capture or trap inbound transport vesicles and to tether Golgi mini-stacks together. This review will summarize our current understanding of coiled coil tethers that are needed for the receipt of transport vesicles at the trans Golgi network (TGN). How do long tethering proteins actually catch vesicles? Golgi-associated, coiled coil tethers contain numerous binding sites for small GTPases, SNARE proteins, and vesicle coat proteins. How are these interactions coordinated and are any or all of them important for the tethering process? Progress toward understanding these questions and remaining, unresolved mysteries will be discussed.

Keywords: Golgi; atomic force microscopy; coiled coil protein; membrane traffic; transport vesicle.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Predicted probability of each amino acid in the sequences of the four TGN Golgins to form a coiled-coil structure. Top to bottom: Golgin-245, GCC185, GCC88, and Golgin-97. The central coiled coil region and the adjacent breaks of GCC185 and Golgin-245 likely form a central bubble.
Figure 2
Figure 2
Sequence alignment of the GRIP domains of human Golgin-245, Golgin-97, GCC88, and GCC185 based on the crystal structure of Golgin-245 generated from PROMALS3D (Pei et al., 2008) and ESPript 3.0 (Robert and Gouet, 2014). The secondary structures of human Golgin-245 are shown above. Invariant residues are in white with red background; similar residues (with global scores between 0.7 and 1.0) are in red, framed in blue, and other residues are in black. Asterisks indicate the invariant tyrosine that is critical for Golgin-245 and Golgin-97 localization and Arl1 binding, as well as the proline in GCC185 that may break helix 2.
Figure 3
Figure 3
Top, the splayed and flexible structure of full length GCC185 (residues 1-1684) detected by atomic force microscopy (AFM). Purified, full length, GFP-GCC185 and purified, N-terminal half-molecules (residues 1-889) deposited on mica (from Cheung et al., 2015). Readily discerned are the N-terminal GFP spheres; most of the molecules showed splayed N-termini, followed by a dimeric region, an unwound central bubble, followed by a short coil and C-terminal GRIP domains. The central bubble sequences were essential for function and could be replaced by random coils, demonstrating that this region needs only to be flexible to sustain vesicle docking at the Golgi. Bottom, collapse model for vesicle tethering at the TGN. Previous models, based upon GMAP210, have suggested that rigid tethers may bend in the middle to bring vesicles closer to the membrane. The AFM studies (Cheung et al., 2015) suggest that tethers may be much more flexible than previously thought, and may collapse onto the membrane surface. Note that the Rab9 GTPase binding site indicated at the GCC185 N-terminus is hypothetical; there are Rab GTPase binding sites along the entire length of GCC185, including a dispensible Rab9 site in the bubble region and an AP-1 binding site C-terminal to the bubble (see text).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Barbero P., Bittova L., Pfeffer S. R. (2002). Visualization of Rab9- mediated vesicle transport from endosomes to the trans-Golgi in living cells. J. Cell Biol. 156, 511–518. 10.1083/jcb.200109030 - DOI - PMC - PubMed
    1. Bardin S., Miserey-Lenkei S., Hurbain I., Garcia-Castillo D., Raposo G., Goud B. (2015). Phenotypic characterisation of RAB6A knockout mouse embryonic fibroblasts. Biol. Cell. 107, 427–439. 10.1111/boc.201400083 - DOI - PubMed
    1. Barr F. A. (1999). A novel Rab6-interacting domain defines a family of Golgi- targeted coiled-coil proteins. Curr. Biol. 9, 381–384. 10.1016/S0960-9822(99)80167-5 - DOI - PubMed
    1. Beard M., Satoh A., Shorter J., Warren G. (2005). A cryptic rab1-binding site in the p115 tethering protein. J. Biol. Chem. 280, 25840–25848. 10.1074/jbc.M503925200 - DOI - PubMed
    1. Behnia R., Panic B., Whyte J. R., Munro S. (2004). Targeting of the Arf-like GTPase Arl3p to the Golgi requires N-terminal acetylation and the membrane protein Sys1p. Nat. Cell Biol. 6, 405–413. 10.1038/ncb1120 - DOI - PubMed

LinkOut - more resources