A Critical Function for the Actin Cytoskeleton in Targeted Exocytosis of Prefusion Vesicles during Myoblast Fusion

Sangjoon Kim, Khurts Shilagardi, Shiliang Zhang, Sabrina N. Hong, Kristin L. Sens, Jinyan Bo, Guillermo A. Gonzalez, Elizabeth Chen

Research output: Contribution to journalArticle

150 Scopus citations

Abstract

Myoblast fusion is an essential step during muscle differentiation. Previous studies in Drosophila have revealed a signaling pathway that relays the fusion signal from the plasma membrane to the actin cytoskeleton. However, the function for the actin cytoskeleton in myoblast fusion remains unclear. Here we describe the characterization of solitary (sltr), a component of the myoblast fusion signaling cascade. sltr encodes the Drosophila ortholog of the mammalian WASP-interacting protein. Sltr is recruited to sites of fusion by the fusion-competent cell-specific receptor Sns and acts as a positive regulator for actin polymerization at these sites. Electron microscopy analysis suggests that formation of F-actin-enriched foci at sites of fusion is involved in the proper targeting and coating of prefusion vesicles. These studies reveal a surprising cell-type specificity of Sltr-mediated actin polymerization in myoblast fusion, and demonstrate that targeted exocytosis of prefusion vesicles is a critical step prior to plasma membrane fusion.

Original languageEnglish (US)
Pages (from-to)571-586
Number of pages16
JournalDevelopmental cell
Volume12
Issue number4
DOIs
StatePublished - Apr 1 2007

Keywords

  • CELLBIO
  • DEVBIO

ASJC Scopus subject areas

  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Developmental Biology
  • Cell Biology

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