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Membrane trafficking in the yeast Saccharomyces cerevisiae model.

Feyder S, De Craene JO, Bär S, Bertazzi DL, Friant S - Int J Mol Sci (2015)

Bottom Line: They have isolated yeast sec mutants unable to secrete an extracellular enzyme and these SEC genes were identified as encoding key effectors of the secretory machinery.Plasma membrane proteins can be internalized by endocytosis (END) and transported to endosomes where they are sorted between those targeted for vacuolar degradation and those redirected to the Golgi (recycling or RCY pathway).Studies in yeast S. cerevisiae allowed the identification of most of the known effectors, protein complexes, and trafficking pathways in eukaryotic cells, and most of them are conserved among eukaryotes.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Genetics, UMR7156, Université de Strasbourg and CNRS, 21 rue Descartes, Strasbourg 67084, France. sergefeyder@hotmail.com.

ABSTRACT
The yeast Saccharomyces cerevisiae is one of the best characterized eukaryotic models. The secretory pathway was the first trafficking pathway clearly understood mainly thanks to the work done in the laboratory of Randy Schekman in the 1980s. They have isolated yeast sec mutants unable to secrete an extracellular enzyme and these SEC genes were identified as encoding key effectors of the secretory machinery. For this work, the 2013 Nobel Prize in Physiology and Medicine has been awarded to Randy Schekman; the prize is shared with James Rothman and Thomas Südhof. Here, we present the different trafficking pathways of yeast S. cerevisiae. At the Golgi apparatus newly synthesized proteins are sorted between those transported to the plasma membrane (PM), or the external medium, via the exocytosis or secretory pathway (SEC), and those targeted to the vacuole either through endosomes (vacuolar protein sorting or VPS pathway) or directly (alkaline phosphatase or ALP pathway). Plasma membrane proteins can be internalized by endocytosis (END) and transported to endosomes where they are sorted between those targeted for vacuolar degradation and those redirected to the Golgi (recycling or RCY pathway). Studies in yeast S. cerevisiae allowed the identification of most of the known effectors, protein complexes, and trafficking pathways in eukaryotic cells, and most of them are conserved among eukaryotes.

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The endocytic internalization process. Endocytosis sites are first initiated by the recruitment of clathrin via the AP-2 adaptor complex (early coat) to cluster cargo proteins to the endocytic invagination sites at the plasma membrane (PM). Initiation is terminated by the recruitment of ANTH- (AP180 N-terminal homology) and ENTH- (epsin N-terminal homology) domain containing proteins Sla2 and epsins Ent1 and Ent2 to form the late coat. Invagination starts by the recruitment of the WASP/Myosin module to initiate actin branched polymerization by the actin module (Arp2/3 complex and actin). Myosin is squeezing the PM while the actin module expands the invagination. Once the invagination in long enough, the fission module starts pinching off vesicles that are released into the cytoplasm.
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ijms-16-01509-f004: The endocytic internalization process. Endocytosis sites are first initiated by the recruitment of clathrin via the AP-2 adaptor complex (early coat) to cluster cargo proteins to the endocytic invagination sites at the plasma membrane (PM). Initiation is terminated by the recruitment of ANTH- (AP180 N-terminal homology) and ENTH- (epsin N-terminal homology) domain containing proteins Sla2 and epsins Ent1 and Ent2 to form the late coat. Invagination starts by the recruitment of the WASP/Myosin module to initiate actin branched polymerization by the actin module (Arp2/3 complex and actin). Myosin is squeezing the PM while the actin module expands the invagination. Once the invagination in long enough, the fission module starts pinching off vesicles that are released into the cytoplasm.

Mentions: In S. cerevisiae, endocytosis was shown to be mainly actin dependent based on genetic screens allowing the isolation of end (endocytosis) mutants [54,55]. Indeed, characterization of these end mutants and others isolated in different genetic screens revealed that the mutated genes are coding for actin (Act1), actin related proteins (Arp2/Arp3), actin polymerization effectors WASP (Wiskott-Aldrich Syndrome Protein) (Las17) or actin cytoskeleton linked-effectors (Sla2, Pan1, Rvs161/167) [55,56,57]. The role of these different proteins into the endocytic internalization step is described in Figure 4.


Membrane trafficking in the yeast Saccharomyces cerevisiae model.

Feyder S, De Craene JO, Bär S, Bertazzi DL, Friant S - Int J Mol Sci (2015)

The endocytic internalization process. Endocytosis sites are first initiated by the recruitment of clathrin via the AP-2 adaptor complex (early coat) to cluster cargo proteins to the endocytic invagination sites at the plasma membrane (PM). Initiation is terminated by the recruitment of ANTH- (AP180 N-terminal homology) and ENTH- (epsin N-terminal homology) domain containing proteins Sla2 and epsins Ent1 and Ent2 to form the late coat. Invagination starts by the recruitment of the WASP/Myosin module to initiate actin branched polymerization by the actin module (Arp2/3 complex and actin). Myosin is squeezing the PM while the actin module expands the invagination. Once the invagination in long enough, the fission module starts pinching off vesicles that are released into the cytoplasm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4307317&req=5

ijms-16-01509-f004: The endocytic internalization process. Endocytosis sites are first initiated by the recruitment of clathrin via the AP-2 adaptor complex (early coat) to cluster cargo proteins to the endocytic invagination sites at the plasma membrane (PM). Initiation is terminated by the recruitment of ANTH- (AP180 N-terminal homology) and ENTH- (epsin N-terminal homology) domain containing proteins Sla2 and epsins Ent1 and Ent2 to form the late coat. Invagination starts by the recruitment of the WASP/Myosin module to initiate actin branched polymerization by the actin module (Arp2/3 complex and actin). Myosin is squeezing the PM while the actin module expands the invagination. Once the invagination in long enough, the fission module starts pinching off vesicles that are released into the cytoplasm.
Mentions: In S. cerevisiae, endocytosis was shown to be mainly actin dependent based on genetic screens allowing the isolation of end (endocytosis) mutants [54,55]. Indeed, characterization of these end mutants and others isolated in different genetic screens revealed that the mutated genes are coding for actin (Act1), actin related proteins (Arp2/Arp3), actin polymerization effectors WASP (Wiskott-Aldrich Syndrome Protein) (Las17) or actin cytoskeleton linked-effectors (Sla2, Pan1, Rvs161/167) [55,56,57]. The role of these different proteins into the endocytic internalization step is described in Figure 4.

Bottom Line: They have isolated yeast sec mutants unable to secrete an extracellular enzyme and these SEC genes were identified as encoding key effectors of the secretory machinery.Plasma membrane proteins can be internalized by endocytosis (END) and transported to endosomes where they are sorted between those targeted for vacuolar degradation and those redirected to the Golgi (recycling or RCY pathway).Studies in yeast S. cerevisiae allowed the identification of most of the known effectors, protein complexes, and trafficking pathways in eukaryotic cells, and most of them are conserved among eukaryotes.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Genetics, UMR7156, Université de Strasbourg and CNRS, 21 rue Descartes, Strasbourg 67084, France. sergefeyder@hotmail.com.

ABSTRACT
The yeast Saccharomyces cerevisiae is one of the best characterized eukaryotic models. The secretory pathway was the first trafficking pathway clearly understood mainly thanks to the work done in the laboratory of Randy Schekman in the 1980s. They have isolated yeast sec mutants unable to secrete an extracellular enzyme and these SEC genes were identified as encoding key effectors of the secretory machinery. For this work, the 2013 Nobel Prize in Physiology and Medicine has been awarded to Randy Schekman; the prize is shared with James Rothman and Thomas Südhof. Here, we present the different trafficking pathways of yeast S. cerevisiae. At the Golgi apparatus newly synthesized proteins are sorted between those transported to the plasma membrane (PM), or the external medium, via the exocytosis or secretory pathway (SEC), and those targeted to the vacuole either through endosomes (vacuolar protein sorting or VPS pathway) or directly (alkaline phosphatase or ALP pathway). Plasma membrane proteins can be internalized by endocytosis (END) and transported to endosomes where they are sorted between those targeted for vacuolar degradation and those redirected to the Golgi (recycling or RCY pathway). Studies in yeast S. cerevisiae allowed the identification of most of the known effectors, protein complexes, and trafficking pathways in eukaryotic cells, and most of them are conserved among eukaryotes.

Show MeSH
Related in: MedlinePlus