Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Actin Cytoskeleton / metabolism
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Actin Cytoskeleton / ultrastructure
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Caveolae / metabolism
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Caveolin 1 / metabolism*
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Cell Adhesion
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Focal Adhesions / metabolism
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Gene Knockdown Techniques
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HeLa Cells
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Humans
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Protein Subunits / metabolism
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Protein Transport
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RNA, Small Interfering / genetics
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Vesicular Transport Proteins / genetics
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Vesicular Transport Proteins / metabolism*
Substances
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CAV1 protein, human
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Caveolin 1
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EXOC7 protein, human
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Protein Subunits
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RNA, Small Interfering
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Vesicular Transport Proteins
Grants and funding
Support was provided to PC by Association pour la Recherche sur le Cancer.(grant # SL220100601356) and Agence Nationale pour la Recherche (grant # ANR-08-BLAN-0111). Core funding for this work was provided by Institut Curie and Centre National de la Recherche Scientifique (National Center for Scientific Research, France). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.