Smooth muscle alpha-actinin binds tightly to fesselin and attenuates its activity toward actin polymerization.
Fesselin is an actin binding protein from smooth muscle that nucleates actin polymerization in a Ca(++)-calmodulin dependent manner, bundles actin and inhibits the actin-activated ATPase activity of myosin S1. We now report that fesselin binds to smooth muscle alpha-actinin. Binding was measured by blot overlay, affinity chromatography and sedimentation methods. Binding was moderate with an association constant of 1-4 x 10(7) M(-1) assuming a 1:1 association of fesselin with alpha-actinin. Fesselin binds to the central spectrin domain repeat region of alpha-actinin but not to the CH1-CH2 domain. Fesselin accelerates the polymerization of actin. This activity of fesselin was attenuated by alpha-actinin. These observations support the role of fesselin in organizing the cytoskeleton.
Pham
Minh
M
Brody School of Medicine at East Carolina University, 600 Moye Blvd., Greenville, NC 27834, USA.
Chalovich
Joseph M
JM
D008841:Actin Cytoskeleton / Q000378:metabolism*; D000185:Actinin / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites / Q000502:physiology; D001704:Biopolymers / Q000378:metabolism; D002417:Cattle; D003599:Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008840:Microfilament Proteins / Q000737:chemistry / Q000378:metabolism*; D009130:Muscle, Smooth / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D011817:Rabbits; D014422:Turkeys
D001704:Biopolymers; D008565:Membrane Proteins; D008840:Microfilament Proteins; C443099:fesselin; D000185:Actinin