Involvement of actin polymerization in podosome dynamics

Chen Luxenburg, Sabina Winograd-Katz, Lia Addadi, Benjamin Geiger*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Summary Podosomes, which are formed by different monocyte derivatives, are small adhesion structures whose coordinated dynamics and cytoskeletal reorganization drive their motile and invasive features. Using live-cell microscopy, we explored the temporal molecular steps of the de novo assembly and disassembly of podosomes in cultured osteoclasts. We demonstrate here that the earliest visible step in podosome assembly is the local accumulation of the plaque protein paxillin, along with cortactin, which stabilizes actin networks, followed by robust polymerization of actin filaments and their association with α-actinin. Only then is a local increase in integrin β3 levels apparent in the podosome ring domain. Thus, local actin polymerization in cortactin- and paxillin-rich locations nucleates podosome assembly before the local accumulation of β3 integrin. We further show that actin polymerization is also important for the recruitment and maintenance of plaque proteins in the mature podosome ring domain. Our model implies that core bundle dynamics play a central role in regulating podosome stability.

Original languageEnglish
Pages (from-to)1666-1672
Number of pages7
JournalJournal of Cell Science
Issue number7
StatePublished - 2012
Externally publishedYes


  • Actin dynamics
  • Actin polymerization
  • Integrin adhesion
  • Osteoclast
  • Podosome
  • Sealing zone


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