A novel microfluidic approach allows the analysis of the dynamics of individual actin filaments, revealing both their local ADP/ADP-Pi-actin composition and that Pi release is a random mechanism

Antoine Jégou

B Bugyi

C Combeau

C Le Clainche

C Valentin-Ranc

D Pantaloni

D Vavylonis

Dominique Didry

E. B Stukalin

E. D Korn

E. G Yarmola

Guillaume Romet-Lemonne

H Isambert

H. J Kinosian

H. Y Kueh

I Fujiwara

I Gutsche-Perelroizen

J. A Spudich

J. R Kuhn

József Orbán

K Murakami

L Blanchoin

L. R Brewer

M Bindschadler

M. B Smith

M. F Carlier

M. R Bubb

Marie-France Carlier

P Ranjith

P Tabeling

R Gieselmann

R Melki

Reinhard Lipowsky

S Romero

T Ohm

T. D Pollard

Thomas Niedermayer

Thomas Pollard

X Li

English

PubMed

Jegou, A.

Niedermayer, T.

Orban, J.

Didry, D.

Lipowsky, R.

Carlier, M.

Romet-Lemonne, G.

MPG.PuRe

Individual actin filaments in a microfluidic flow reveal the mechanism of ATP hydrolysis and give insight into the properties of profilin

Individual Actin Filaments in a Microfluidic Flow Reveal the Mechanism of ATP Hydrolysis and Give Insight Into the Properties of Profilin

The hydrolysis of ATP associated with actin and profilin-actin polymerization is pivotal in cell motility. It is at the origin of treadmilling of actin filaments and controls their dynamics and mechanical properties, as well as their interactions with regulatory proteins. The slow release of inorganic phosphate (Pi) that follows rapid cleavage of ATP gamma phosphate is linked to an increase in the rate of filament disassembly. The mechanism of Pi release in actin filaments has remained elusive for over 20 years. Here, we developed a microfluidic setup to accurately monitor the depolymerization of individual filaments and determine their local ADP-Pi content. We demonstrate that Pi release in the filament is not a vectorial but a random process with a half-time of 102 seconds, irrespective of whether the filament is assembled from actin or profilin-actin. Pi release from the depolymerizing barbed end is faster (half-time of 0.39 seconds) and further accelerated by profilin. Profilin accelerates the depolymerization of both ADP- and ADP-Pi-F-actin. Altogether, our data show that during elongation from profilin-actin, the dissociation of profilin from the growing barbed end is not coupled to Pi release or to ATP cleavage on the terminal subunit. These results emphasize the potential of microfluidics in elucidating actin regulation at the scale of individual filaments

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Individual actin filaments in a microfluidic flow reveal the mechanism of ATP hydrolysis and give insight into the properties of profilin.

Jégou Antoine

Niedermayer Thomas

Orbán József

Didry Dominique

Lipowsky Reinhard

Carlier Marie-France

Romet-Lemonne Guillaume

Public Library of Science (PLOS)

Marie-france Carlier

Guillaume Romet-lemonne

CiteSeerX

Crossref

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Wegner A

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3181223

Individual Actin Filaments in a Microfluidic Flow Reveal the Mechanism of ATP Hydrolysis and Give Insight Into the Properties of Profilin

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MPG.PuRe

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Directory of Open Access Journals

Public Library of Science (PLOS)

CiteSeerX

Crossref