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Direct real-time observation of actin filament branching mediated by Arp2/3 complex using total internal reflection fluorescence microscopy.

ABSTRACT: Existing methods for studying actin filament dynamics have allowed analysis only of bulk samples or individual filaments after treatment with the drug phalloidin, which perturbs filament dynamics. Total internal reflection fluorescence microscopy with rhodamine-labeled actin allowed us to observe polymerization in real time, without phalloidin. Direct measurements of filament growth confirmed the rate constants measured by electron microscopy and established that rhodamine actin is a kinetically inactive tracer for imaging. In the presence of activated Arp2/3 complex, growing actin filaments form branches at random sites along their sides, rather than preferentially from their barbed ends.

SUBMITTER: Amann KJ

PROVIDER: S-EPMC64974 | biostudies-literature | 2001 Dec

REPOSITORIES: biostudies-literature

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Direct real-time observation of actin filament branching mediated by Arp2/3 complex using total internal reflection fluorescence microscopy.

Amann K J KJ Pollard T D TD

Proceedings of the National Academy of Sciences of the United States of America 20011211 26

Existing methods for studying actin filament dynamics have allowed analysis only of bulk samples or individual filaments after treatment with the drug phalloidin, which perturbs filament dynamics. Total internal reflection fluorescence microscopy with rhodamine-labeled actin allowed us to observe polymerization in real time, without phalloidin. Direct measurements of filament growth confirmed the rate constants measured by electron microscopy and established that rhodamine actin is a kinetically ...[more]

PMID: 11742068

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