Spatial dynamics of receptor-mediated endocytic trafficking in budding yeast revealed by using fluorescent α-factor derivatives

Junko Y. Toshima, Jiro Toshima, Marko Kaksonen, Adam C. Martin, David S. King, David G. Drubin

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    121 Citations (Scopus)


    Much progress defining the order and timing of endocytic internalization events has come as a result of real-time, live-cell fluorescence microscopy. Although the availability of numerous endocytic mutants makes yeast an especially valuable organism for functional analysis of endocytic dynamics, a serious limitation has been the lack of a fluorescent cargo for receptor-mediated endocytosis. We have now synthesized biologically active fluorescent mating-pheromone derivatives and demonstrated that receptor-mediated endocytosis in budding yeast occurs via the clathrin- and actin-mediated endocytosis pathway. We found that endocytic proteins first assemble into patches on the plasma membrane, and then α-factor associates with the patches. Internalization occurs next, concomitant with actin assembly at patches. Additionally, endocytic vesicles move toward early endosomes on actin cables. Early endosomes also associate with actin cables, and they actively move toward endocytic sites to capture vesicles being released from the plasma membrane. Thus, endocytic vesicle formation and capture of the newly released vesicles by early endosomes occur in a highly concerted manner, mediated by the actin cytoskeleton.

    Original languageEnglish
    Pages (from-to)5793-5798
    Number of pages6
    JournalProceedings of the National Academy of Sciences of the United States of America
    Issue number15
    Publication statusPublished - 2006 Apr 11



    • Actin
    • Cytoskeleton
    • Endocytosis
    • Endosome

    ASJC Scopus subject areas

    • Genetics
    • General

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