These animations were designed and created by Bruce Goode and Julian Eskin, and are made available for download and use under the Creative Commons 4.0 Attribution License, except where noted otherwise. Animations were created primarily using Blender and Adobe After Effects software.
Spontaneous actin nucleation
ATP-bound actin monomers spontaneously form short-lived dimers, and occasionally lead to the formation of larger oligomers, creating new filaments.
Cellular barriers to actin nucleation
Despite the high concentration of actin monomers in cells, they do not readily form new filaments in the absence of actin nucleators. This is due to the presence of several barriers to actin nucleation, including Profilin, Thymosin beta 4, and Capping Protein.
Actin nucleation by the Arp2/3 complex
Nucleation of a daughter filament by the combined actions of Arp2/3 complex and a nucleation-promoting factor (NPF).
Actin nucleation by Formin
Nucleation of an unbranched actin filament by the FH1 and FH2 domains of a formin. The FH2 domain stabilizes a spontaneously formed actin dimer to nucleate a new filament, and then processively rides the growing barbed end while the FH1 domain recruits profilin-bound actin monomers to accelerate filament elongation.
Actin nucleation by Spire
Molecular animation showing the nucleation of an actin filament by Spire. The tandem WH2 domains in Spire recruit and organize several actin monomers, which are then joined by additional actin monomers from solution as a filament beings to grow.
Collaborative Actin filament nucleation
by Spire & Formin
Working model for collaborative actin nucleation by Spire and formin. Two Spire molecules bind to the C-terminal tails of the formin via their KIND domains and then recruit actin monomers using their WH2 domains. The formin FH2 domain stabilizes and elongates the nascent filament.
Membrane traffic animation made by Julian Eskin for laboratory of Avital Rodal.