Crn7 Interacts with AP-1 and Is Required for the Maintenance of Golgi Morphology and Protein Export from the Golgi

Rybakin, Vasily; Gounko, Natalia V.; Späte, Kira; Höning, Stefan; Majoul, Irina; Duden, Rainer; Noegel, Angelika A.

doi:10.1074/jbc.m604680200

Cited by 33 publications

(33 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Disruption of AP-1B function by microinjection of AP-1B antibody (Cancino et al, 2007) or knockdown of AP-1B has been reported to block the sorting of VSVG to the basolateral surface in polarized epithelial cells. In nonpolarized cells, the interaction of AP-1 and Crn7 was shown to be required for the export of VSVG from the Golgi (Rybakin et al, 2006). The cell types used in this current study are nonpolarized and, therefore, most likely express exclusively AP-1A.…”

Section: A Novel Function For Eps15 In the Transport Of Nascentmentioning

confidence: 87%

Eps15 Mediates Vesicle Trafficking from thetrans-Golgi Network via an Interaction with the Clathrin Adaptor AP-1

Chi

Cao

Chen

et al. 2008

MBoC

View full text Add to dashboard Cite

Eps15 (EGFR pathway substrate clone 15) is well known for its role in clathrin-coated vesicle formation at the plasma membrane through interactions with other clathrin adaptor proteins such as AP-2. Interestingly, we observed that in addition to its plasma membrane localization, Eps15 is also present at the trans-Golgi network (TGN). Therefore, we predicted that Eps15 might associate with clathrin adaptor proteins at the TGN and thereby mediate the formation of Golgi-derived vesicles. Indeed, we have found that Eps15 and the TGN clathrin adaptor AP-1 coimmunoprecipitate from rat liver Golgi fractions. Furthermore, we have identified a 14-amino acid motif near the AP-2-binding domain of Eps15 that is required for binding to AP-1, but not AP-2. Disruption of the Eps15-AP-1 interaction via siRNA knockdown of AP-1 or expression of mutant Eps15 protein, which lacks a 14-amino acid motif representing the AP-1 binding site of Eps15, significantly reduced the exit of secretory proteins from the TGN. Together, these findings indicate that Eps15 plays an important role in clathrin-coated vesicle formation not only at the plasma membrane but also at the TGN during the secretory process. INTRODUCTIONClathrin-coated vesicles and associated adaptor proteins play an important role in the cyclical pattern of membrane trafficking throughout the endocytic and secretory pathways (Traub, 2005;McNiven and Thompson, 2006). Conventional clathrin adaptors, such as the adaptor protein (AP) complexes AP-1, -2, -3, and -4, are known to sequester and link membrane cargoes to the clathrin lattice while recruiting other accessory proteins that aid in the formation of the clathrin basket (Robinson and Bonifacino, 2001;Owen et al., 2004;Robinson, 2004;Ungewickell and Hinrichsen, 2007). Although dozens of these additional adaptor proteins, including Eps15 (EGFR pathway substrate clone 15), epsin, AP180, and amphiphysin to name just a few, are known to interact with AP-2 and mediate vesicle formation from the plasma membrane (Schmid and McMahon, 2007), information regarding clathrin-based adaptors at the trans-Golgi network (TGN) is less extensive (Traub, 2003(Traub, , 2005Sorkin, 2004;McNiven and Thompson, 2006). The endocytic adaptor Eps15 was originally identified as a substrate of the EGFR (Fazioli et al., 1993) and is well known to participate in clathrin-mediated endocytosis. As examples, Eps15 localizes to plasma membrane clathrin-coated pits and vesicles (Tebar et al., 1996;van Delft et al., 1997) and is recruited to the plasma membrane upon epidermal growth factor receptor (EGFR) activation (Torrisi et al., 1999). In addition, disruption of Eps15 function through injection of cells with antibodies against Eps15 or expression of Eps15 mutants inhibits the internalization of both EGF and transferrin (Carbone et al., 1997;Benmerah et al., 1998Benmerah et al., , 1999Benmerah et al., , 2000.The multiple interaction domains of Eps15 make it well suited to function as an endocytic adaptor. Its N-terminal domain contains three Eps15 homology (E...

show abstract

Section: A Novel Function For Eps15 In the Transport Of Nascentmentioning

confidence: 87%

Eps15 Mediates Vesicle Trafficking from thetrans-Golgi Network via an Interaction with the Clathrin Adaptor AP-1

Chi

Cao

Chen

et al. 2008

MBoC

View full text Add to dashboard Cite

show abstract

“…It is possible that the N-terminal half of CRN7 has a negative effect on Tob degradation and that a conformational change in CRN7 in response to cellular signaling modulates the activity. CRN7 is known to participate in the regulation of Golgi trafficking [18,19]; however, its involvement in proteosome-mediated degradation has not been reported. We show here for the first time that CRN7 forms a novel E3 ligase complex.…”

Section: Discussionmentioning

confidence: 99%

“…RNA interference-mediated inhibition of CRN7 results in morphological changes in the Golgi apparatus and the subsequent disruption of anterograde Golgi-to-plasma membrane transport [19]. Since CRN7 interacts with the clathrin adaptor AP-1, the function of CRN7 may be important for clathrin-dependent membrane trafficking [18,19].…”

Section: Introductionmentioning

confidence: 99%

Coronin7 forms a novel E3 ubiquitin ligase complex to promote the degradation of the anti-proliferative protein Tob

et al. 2010

View full text Add to dashboard Cite

a b s t r a c tTob belongs to the anti-proliferative Tob/BTG family. The level of Tob throughout the cell cycle is regulated by the SCF (Skp1/Cullin/F-box protein)Skp2 ubiquitin ligase (E3) complex. Here, we show that Coronin7 (CRN7) is also involved in Tob degradation. We identified CRN7 as a Tob-interacting molecule. A sequence containing two of the six WD motifs in the middle of CRN7 was responsible for the interaction. CRN7 enhanced the polyubiquitination of Tob in vitro, and overexpression of CRN7 promoted proteasome-dependent degradation of Tob. Furthermore, CRN7 interacted with Cullin1 and Roc1 to form a novel SCF-like E3 complex, suggesting that Tob protein is regulated by multiple ubiquitination machineries. Structured summary:Cullin1 physically interacts with CRN7: shown by anti tag coimmunoprecipitation (view interaction) Roc1 physically interacts with CRN7: shown by anti tag coimmunoprecipitation (view interaction) CRN7 physically interacts with Tob1: shown by anti tag coimmunoprecipitation (view interaction) CDC34 physically interacts with CRN7: shown by anti tag coimmunoprecipitation (view interaction) Tob1 and CRN7 colocalize: shown by fluorescence microscopy (view interaction) Elongin B physically interacts with CRN7: shown by anti tag coimmunoprecipitation (view interaction) Elongin C physically interacts with CRN7: shown by anti tag coimmunoprecipitation (view interaction) Tob1 physically interacts with CRN7: shown by two hybrid (view interaction)

show abstract

“…The following siRNA were used: targeting human m1-adaptin -validated siRNA cat. # SI00299187 (Qiagen; no sequence information provided by vendor); targeting human Crn7 -siRNA (8) 2454 [7]; control: siCONTROL Non-Targeting siRNA Pool cat. # D-001206-13 (Dharmacon; no sequence information provided by vendor).…”

Section: Methodsmentioning

confidence: 99%

“…Such proteins have been studied in Caenorhabditis elegans and Drosophila melanogaster, and mutant phenotypes suggest that they play a role in vesicular trafficking, embryonic axis formation and axonal guidance [4,5]. We recently demonstrated that the only human dual WD domain coronin, the Coronin-7 (Crn7), differs from the rest of the family in that it localizes to the Golgi complex and is required for the maintenance of Golgi morphology and for protein export from the Golgi [6,7]. Depletion of Crn7 by RNAi leads to Golgi breakdown and retention of VSVG in the Golgi upon a shift to the permissive temperature.…”

Section: Introductionmentioning

confidence: 99%

Molecular mechanism underlying the association of Coronin-7 with Golgi membranes

Rybakin

Rastetter

Stumpf

et al. 2008

Cell. Mol. Life Sci.

View full text Add to dashboard Cite

Coronin-7 (Crn7) is a ubiquitous mammalian WD40-repeat protein that localizes to the Golgi complex, interacts with AP-1 adaptor complex via binding of a tyrosine-288-based sorting signal to the mu1-subunit of AP-1, and participates in the maintenance of the Golgi structure and function. Here, we define the requirements for the recruitment of Crn7 from the cytosol to the Golgi. We establish that Src activity is indispensable for the interaction of Crn7 with Golgi membranes. Crn7 binds Src in vivo and can be phosphorylated by recombinant Src in vitro. We demonstrate that tyrosine-758 is the major Src phosphorylation site. Further, to be targeted to membranes Crn7 requires the presence of cargo in the Golgi complex. Finally, downregulation of the mu1-subunit of AP-1 leads to the dispersal of Crn7 from the Golgi membranes. We propose a mechanism whereby sequential events of protein interaction and posttranslational modification result in the membrane targeting of Crn7.

show abstract

Crn7 Interacts with AP-1 and Is Required for the Maintenance of Golgi Morphology and Protein Export from the Golgi

Cited by 33 publications

References 32 publications

Eps15 Mediates Vesicle Trafficking from thetrans-Golgi Network via an Interaction with the Clathrin Adaptor AP-1

Eps15 Mediates Vesicle Trafficking from thetrans-Golgi Network via an Interaction with the Clathrin Adaptor AP-1

Coronin7 forms a novel E3 ubiquitin ligase complex to promote the degradation of the anti-proliferative protein Tob

Molecular mechanism underlying the association of Coronin-7 with Golgi membranes

Contact Info

Product

Resources

About