Localization of beta-actinin in the Z lines of chicken breast muscle, as detected with a monoclonal antibody specific to the beta I subunit (Cap Z alpha).
Immunofluorescence microscopy showed that a monoclonal antibody, 2F3, specific to the beta I subunit (Cap Z alpha) of beta-actinin (Cap Z) bound to the Z lines of chicken breast muscle. When myofibrils were briefly extracted with 0.6 M KI, the reactivity of the Z lines with 2F3 was very weak, but on subsequent treatment with purified beta-actinin, the antibody binding recovered. beta-Actinin inhibited elongation of the actin filaments of isolated I-Z-I brushes, myosin-extracted sarcomeres, on the addition of G-actin. However, when an increased concentration of G-actin was added, the inhibitory action of beta-actinin became negligible, suggesting that beta-actinin did not cap the pointed end of an actin filament in a myofibril.
Ito
M
M
Department of Biology, Faculty of Science, Chiba University.
Hirono
Y
Y
Watanabe
S
S
Yamamoto
H
H
Maruyama
K
K
D000185:Actinin / Q000276:immunology / Q000378:metabolism*; D000199:Actins / Q000378:metabolism / Q000648:ultrastructure; D000818:Animals; D000911:Antibodies, Monoclonal; D001665:Binding Sites; D015153:Blotting, Western; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005455:Fluorescent Antibody Technique; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D009132:Muscles / Q000378:metabolism*
D000199:Actins; D000911:Antibodies, Monoclonal; D000185:Actinin