Polymorphism of cross-linked actin networks in giant vesicles.
Actin networks cross-linked by natural linkers alpha-actinin and filamin are generated in giant vesicles by polymerization through ionophore-mediated influx of Mg2+. alpha-actinin induces the formation of randomly linked networks at 25 degrees C which transform at <15 degrees C into spiderweblike gels or ringlike bundles depending on the vesicle size. Muscle filamin forms ringlike structures under all experimental conditions which can supercoil by subsequent Mg2+ addition. The polymorphism is rationalized in terms of recent models of bivalent ion coupled semiflexible polyelectrolytes and by considering the topology of the linkers.
Limozin
Laurent
L
E22-Biophysics, Physics Department, Technical University Munich, James Franck Strasse, 85748 Garching, Germany. llimozin@ph.tum.de
Sackmann
Erich
E
D000199:Actins / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D002784:Cholesterol / Q000737:chemistry; D003285:Contractile Proteins / Q000737:chemistry / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry; D064448:Filamins; D008081:Liposomes; D008274:Magnesium / Q000737:chemistry; D008840:Microfilament Proteins / Q000737:chemistry / Q000378:metabolism; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008956:Models, Chemical; D009132:Muscles / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry; D011817:Rabbits; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D014422:Turkeys
D000199:Actins; D003285:Contractile Proteins; D003432:Cross-Linking Reagents; D064448:Filamins; D008081:Liposomes; D008840:Microfilament Proteins; D010743:Phospholipids; D002784:Cholesterol; D008274:Magnesium