biostudies-literatureLuxenburg CNIGMS NIH HHS1666-72https://www.ebi.ac.uk/biostudies/studies/S-EPMC3346827biostudies-literatureUnknown125(Pt 7)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 podosomeJournal of cell scienceInvolvement of actin polymerization in podosome dynamics.PMC3346827U54 GM064346U54GM64346Winograd-Katz SAddadi LGeiger BLuxenburg CfalseInvolvement of actin polymerization in podosome dynamics.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 podosome2012-01-01T00:00:00Z2012 Apr2025-04-18T20:46:30.855Z2019-03-27T00:53:13ZS-EPMC33468272232850710.1242/jcs.075903