Report

Actin-Propelled Invasive Membrane Protrusions Promote Fusogenic Protein Engagement During Cell-Cell Fusion

See allHide authors and affiliations

Science  19 Apr 2013:
Vol. 340, Issue 6130, pp. 359-363
DOI: 10.1126/science.1234781

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

To Fuse or Not to Fuse?

Cell-cell fusion is poorly understood, although we know that in the nematode, Caenorhabditis elegans, it involves cell-surface fusogens and in the fly, Drosophila, the actin cytoskeleton plays a role. Shilagardi et al. (p. 359) reconstituted a high-efficiency, inducible cell-fusion culture system, in which they found that the C. elegans fusogen, Eff-1, induced a low level of cell-cell fusion that was enhanced by coexpression with a cell adhesion molecule, Sticks and stones (Sns), required for myoblast fusion in Drosophila. Sns-enhanced cell-cell fusion was mediated by dynamic actin polymerization that generated invasive membrane protrusions at sites of fusion.

Abstract

Cell-cell fusion is critical for the conception, development, and physiology of multicellular organisms. Although cellular fusogenic proteins and the actin cytoskeleton are implicated in cell-cell fusion, it remains unclear whether and how they coordinate to promote plasma membrane fusion. We reconstituted a high-efficiency, inducible cell fusion culture system in the normally nonfusing Drosophila S2R+ cells. Both fusogenic proteins and actin cytoskeletal rearrangements were necessary for cell fusion, and in combination they were sufficient to impart fusion competence. Localized actin polymerization triggered by specific cell-cell or cell-matrix adhesion molecules propelled invasive cell membrane protrusions, which in turn promoted fusogenic protein engagement and plasma membrane fusion. This de novo cell fusion culture system reveals a general role for actin-propelled invasive membrane protrusions in driving fusogenic protein engagement during cell-cell fusion.

View Full Text