کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2035321 | 1072160 | 2014 | 13 صفحه PDF | دانلود رایگان |
• Worm cell-cell fusion protein EFF-1 is homologous to class II viral fusion proteins
• Lack of fusion loop suggests no insertion into the opposite membrane for fusion
• Distinct fusogenic mechanism in spite of sharing 3D fold with viral fusion proteins
• Results highlight extensive virus-cell genetic exchanges during evolution
SummaryCell-cell fusion proteins are essential in development. Here we show that the C. elegans cell-cell fusion protein EFF-1 is structurally homologous to viral class II fusion proteins. The 2.6 Å crystal structure of the EFF-1 trimer displays the same 3D fold and quaternary conformation of postfusion class II viral fusion proteins, although it lacks a nonpolar “fusion loop,” indicating that it does not insert into the target membrane. EFF-1 was previously shown to be required in both cells for fusion, and we show that blocking EFF-1 trimerization blocks the fusion reaction. Together, these data suggest that whereas membrane fusion driven by viral proteins entails leveraging of a nonpolar loop, EFF-1-driven fusion of cells entails trans-trimerization such that transmembrane segments anchored in the two opposing membranes are brought into contact at the tip of the EFF-1 trimer to then, analogous to SNARE-mediated vesicle fusion, zip the two membranes into one.
Graphical AbstractFigure optionsDownload high-quality image (313 K)Download as PowerPoint slide
Journal: - Volume 157, Issue 2, 10 April 2014, Pages 407–419