Title of article :
Novel Structures for α-Actinin:F-Actin Interactions and their Implications for Actin–Membrane Attachment and Tension Sensing in the Cytoskeleton
Author/Authors :
Cheri M. Hampton، نويسنده , , Dianne W. Taylor، نويسنده , , Kenneth A. Taylor، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Pages :
13
From page :
92
To page :
104
Abstract :
We have applied correspondence analysis to electron micrographs of 2-D rafts of F-actin cross-linked with α-actinin on a lipid monolayer to investigate α-actinin:F-actin binding and cross-linking. More than 8000 actin crossover repeats, each with one to five α-actinin molecules bound, were selected, aligned, and grouped to produce class averages of α-actinin cross-links with ∼9-fold improvement in the stochastic signal-to-noise ratio. Measurements and comparative molecular models show variation in the distance separating actin-binding domains and the angle of the α-actinin cross-links. Rafts of F-actin and α-actinin formed predominantly polar 2-D arrays of actin filaments, with occasional insertion of filaments of opposite polarity. Unique to this study are the numbers of α-actinin molecules bound to successive crossovers on the same actin filament. These “monofilament”-bound α-actinin molecules may reflect a new mode of interaction for α-actinin, particularly in protein-dense actin–membrane attachments in focal adhesions. These results suggest that α-actinin is not simply a rigid spacer between actin filaments, but rather a flexible cross-linking, scaffolding, and anchoring protein. We suggest these properties of α-actinin may contribute to tension sensing in actin bundles.
Keywords :
?-actinin , focal adhesion , actin cytoskeleton , Electron microscopy , image processing
Journal title :
Journal of Molecular Biology
Serial Year :
2007
Journal title :
Journal of Molecular Biology
Record number :
1249259
Link To Document :
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