Structural basis for the slow dynamics of the actin filament pointed end

  • Narita A
  • Oda T
  • Maéda Y
  • 65


    Mendeley users who have this article in their library.
  • 19


    Citations of this article.


The actin filament has clear polarity where one end, the pointed end, has a much slower polymerization and depolymerization rate than the other end, the barbed end. This intrinsic difference of the ends significantly affects all actin dynamics in the cell, which has central roles in a wide spectrum of cellular functions. The detailed mechanism underlying this difference has remained elusive, because high-resolution structures of the filament ends have not been available. Here, we present the structure of the actin filament pointed end obtained using a single particle analysis of cryo-electron micrographs. We determined that the terminal pointed end subunit is tilted towards the penultimate subunit, allowing specific and extra loop-to-loop inter-strand contacts between the two end subunits, which is not possible in other parts of the filament. These specific contacts prevent the end subunit from dissociating. For elongation, the loop-to-loop contacts also inhibit the incorporation of another actin monomer at the pointed end. These observations are likely to account for the less dynamic pointed end.

Author-supplied keywords

  • actin filament
  • cryo-electron microscopy
  • cytoskeleton
  • motor protein
  • single particle analysis

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Akihiro Narita

  • Toshiro Oda

  • Yuichiro Maéda

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free