title: Binding of a native titin fragment to actin is regulated by PIP2.
abstract: Titin is a giant protein which extends from Z-line to M-line in striated muscles. We report here the purification of a 150-kDa titin fragment, obtained after V8 protease treatment of myofibrils. This polypeptide was located at the N1-line level, in a titin part known to exhibit stiff properties correlated to an association with actin. By solid or liquid phase binding assays and cosedimentation, we have clearly demonstrated a direct, saturable and relative high affinity binding of the native titin fragment to F-actin. The 150-kDa titin fragment was also shown to accelerate actin polymerization. Furthermore, the actin-titin interaction was found to be inhibited by phosphoinositides.
authors.affiliation: Laboratoire de Motilité Cellulaire EPHE, UMR 5539, Université des Sciences et Techniques du Languedoc, Montpellier, France. c-astier@crit.univ.montp2.fr
authors.forename: C
authors.initials: C
authors.lastname: Astier
authors.forename: F
authors.initials: F
authors.lastname: Raynaud
authors.forename: M C
authors.initials: MC
authors.lastname: Lebart
authors.forename: C
authors.initials: C
authors.lastname: Roustan
authors.forename: Y
authors.initials: Y
authors.lastname: Benyamin
mesh_terms: D000199:Actins / Q000502:physiology*; D000818:Animals; D064211:Connectin; D009124:Muscle Proteins / Q000302:isolation & purification / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D011108:Polymers; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits
chemical_list: D000199:Actins; D064211:Connectin; D009124:Muscle Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D011108:Polymers; D011494:Protein Kinases