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author:("Le Dez, galle")
1.  Correction: Exo70 Subunit of the Exocyst Complex Is Involved in Adhesion-Dependent Trafficking of Caveolin-1 
PLoS ONE  2013;8(8):10.1371/annotation/fc7791c5-45e2-44ae-868b-f0529c56033f.
doi:10.1371/annotation/fc7791c5-45e2-44ae-868b-f0529c56033f
PMCID: PMC3769203
2.  Exo70 Subunit of the Exocyst Complex Is Involved in Adhesion-Dependent Trafficking of Caveolin-1 
PLoS ONE  2012;7(12):e52627.
Caveolae are specialized domains of the plasma membrane, which play key roles in signaling, endocytosis and mechanosensing. Using total internal reflection fluorescent microscopy (TIRF-M), we observe that the exocyst subunit Exo70 forms punctuate structures at the plasma membrane and partially localizes with caveolin-1, the main component of caveolae. Upon cell detachment, we found that Exo70 accumulates with caveolin-1-positive vesicular structures. Upon cell re-adhesion, caveolin-1 traffics back to the plasma membrane in a multistep process involving microtubules and actin cytoskeleton. In addition, silencing of Exo70 redirects caveolin-1 to focal adhesions identified by markers such as α5 integrin or vinculin. Based on these findings, we conclude that Exo70 is involved in caveolin-1 recycling to the plasma membrane during re-adhesion of the cells to the substratum.
doi:10.1371/journal.pone.0052627
PMCID: PMC3531403  PMID: 23300727
3.  The TFIIH subunit Tfb3 regulates cullin neddylation 
Molecular cell  2011;43(3):488-495.
Summary
Cullin proteins are scaffolds for the assembly of multi-subunit ubiquitin ligases, which ubiquitylate a large number of proteins involved in widely-varying cellular functions. Multiple mechanisms cooperate to regulate cullin activity, including neddylation of their C-terminal domain. Interestingly, we found that the yeast Cul4-type cullin Rtt101 is not only neddylated but also ubiquitylated, and both modifications promote Rtt101 function in vivo. Surprisingly, proper modification of Rtt101 neither correlated with catalytic activity of the RING-domain of Hrt1 nor did it require the Nedd8 ligase Dcn1. Instead, ubiquitylation of Rtt101 was dependent on the ubiquitin-conjugating enzyme Ubc4, while efficient neddylation involves the RING-domain protein Tfb3, a subunit of the transcription factor TFIIH. Tfb3 also controls Cul3 neddylation and activity in vivo, and physically interacts with Ubc4 and the Nedd8-conjugating enzyme Ubc12 as well as the Hrt1/Rtt101 complex. Together, these results suggest that the conserved RING-domain protein Tfb3 controls activation of a subset of cullins.
doi:10.1016/j.molcel.2011.05.032
PMCID: PMC3186349  PMID: 21816351
4.  The interaction of IQGAP1 with the exocyst complex is required for tumor cell invasion downstream of Cdc42 and RhoA 
The Journal of Cell Biology  2008;181(6):985-998.
Invadopodia are actin-based membrane protrusions formed at contact sites between invasive tumor cells and the extracellular matrix with matrix proteolytic activity. Actin regulatory proteins participate in invadopodia formation, whereas matrix degradation requires metalloproteinases (MMPs) targeted to invadopodia. In this study, we show that the vesicle-tethering exocyst complex is required for matrix proteolysis and invasion of breast carcinoma cells. We demonstrate that the exocyst subunits Sec3 and Sec8 interact with the polarity protein IQGAP1 and that this interaction is triggered by active Cdc42 and RhoA, which are essential for matrix degradation. Interaction between IQGAP1 and the exocyst is necessary for invadopodia activity because enhancement of matrix degradation induced by the expression of IQGAP1 is lost upon deletion of the exocyst-binding site. We further show that the exocyst and IQGAP1 are required for the accumulation of cell surface membrane type 1 MMP at invadopodia. Based on these results, we propose that invadopodia function in tumor cells relies on the coordination of cytoskeletal assembly and exocytosis downstream of Rho guanosine triphosphatases.
doi:10.1083/jcb.200709076
PMCID: PMC2426946  PMID: 18541705

Results 1-4 (4)