TY - JOUR
T1 - Structure, Evolutionary Conservation, and Conformational Dynamics of Homo sapiens Fascin-1, an F-actin Crosslinking Protein
AU - Sedeh, Reza Sharifi
AU - Fedorov, Alexander A.
AU - Fedorov, Elena V.
AU - Ono, Shoichiro
AU - Matsumura, Fumio
AU - Almo, Steven C.
AU - Bathe, Mark
N1 - Funding Information:
The authors are grateful to Martin Karplus and Danijela Vignjevic for extensive comments on the manuscript. Funding from the Samuel A. Goldblith Professorship to M.B. and from the NIH to S.C.A. is gratefully acknowledged.
PY - 2010/7
Y1 - 2010/7
N2 - Eukaryotes have several highly conserved actin-binding proteins that crosslink filamentous actin into compact ordered bundles present in distinct cytoskeletal processes, including microvilli, stereocilia and filopodia. Fascin is an actin-binding protein that is present predominantly in filopodia, which are believed to play a central role in normal and aberrant cell migration. An important outstanding question regards the molecular basis for the unique localization and functional properties of fascin compared with other actin crosslinking proteins. Here, we present the crystal structure of full-length Homo sapiens fascin-1, and examine its packing, conformational flexibility, and evolutionary sequence conservation. The structure reveals a novel arrangement of four tandem β-trefoil domains that form a bi-lobed structure with approximate pseudo 2-fold symmetry. Each lobe has internal approximate pseudo 2-fold and pseudo 3-fold symmetry axes that are approximately perpendicular, with β-hairpin triplets located symmetrically on opposite sides of each lobe that mutational data suggest are actin-binding domains. Sequence conservation analysis confirms the importance of hydrophobic core residues that stabilize the β-trefoil fold, as well as interfacial residues that are likely to stabilize the overall fascin molecule. Sequence conservation also indicates highly conserved surface patches near the putative actin-binding domains of fascin, which conformational dynamics analysis suggests to be coupled via an allosteric mechanism that might have important functional implications for F-actin crosslinking by fascin.
AB - Eukaryotes have several highly conserved actin-binding proteins that crosslink filamentous actin into compact ordered bundles present in distinct cytoskeletal processes, including microvilli, stereocilia and filopodia. Fascin is an actin-binding protein that is present predominantly in filopodia, which are believed to play a central role in normal and aberrant cell migration. An important outstanding question regards the molecular basis for the unique localization and functional properties of fascin compared with other actin crosslinking proteins. Here, we present the crystal structure of full-length Homo sapiens fascin-1, and examine its packing, conformational flexibility, and evolutionary sequence conservation. The structure reveals a novel arrangement of four tandem β-trefoil domains that form a bi-lobed structure with approximate pseudo 2-fold symmetry. Each lobe has internal approximate pseudo 2-fold and pseudo 3-fold symmetry axes that are approximately perpendicular, with β-hairpin triplets located symmetrically on opposite sides of each lobe that mutational data suggest are actin-binding domains. Sequence conservation analysis confirms the importance of hydrophobic core residues that stabilize the β-trefoil fold, as well as interfacial residues that are likely to stabilize the overall fascin molecule. Sequence conservation also indicates highly conserved surface patches near the putative actin-binding domains of fascin, which conformational dynamics analysis suggests to be coupled via an allosteric mechanism that might have important functional implications for F-actin crosslinking by fascin.
KW - Actin-binding protein
KW - Cancer
KW - Cell motility
KW - F-actin bundle
KW - Molecular simulation
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U2 - 10.1016/j.jmb.2010.04.043
DO - 10.1016/j.jmb.2010.04.043
M3 - Article
C2 - 20434460
AN - SCOPUS:77954386574
SN - 0022-2836
VL - 400
SP - 589
EP - 604
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 3
ER -