Effects of Exogenous β-Actinin(CapZ)on Actin Filamentous Structures in Cultured Muscle Cells

概要

論文の詳細を見る
β-Actinin(CapZ)is a heterodimeric actin-binding protein which is localized in the Z-bands of myofibril. It caps the barbed end of actin filaments and nucleates actin-polymerization in a Ca^+2-independent manner. As judged by these properties of β-actinin, it is conceivable that β-actinin is involved in the regulation of actin assembly, especially in the formation of I-Z-I complex during myofibrillogenesis. In this stidy, to examine the function of β-actinin in myofibrillogenesis, recombinant β-actinin(r-β-actinin)produced in an E.coli expression system was introduced into cultured myogenic cells by a microinjection method. Stress fibers in C2 myoblasts were disrupted soon after microinjection of recombinant β-actinin, but nascent as well as well-organized myofibrils were scarcely affected by exogenous β-actinin. Based on these observations, we suggest that in myoblasts where actin filaments are dynamically reorganized, reassembly process of actin filaments may be affected by the exogenous β-actinin, whereas actin filaments become more stable and less sensitive to exogenous β-actinin, when they are organized into myofibrillar structures and anchored to Z-lines in myotubes.
社団法人日本動物学会の論文