Beta-actinin isoforms in various types of muscle and non-muscle tissues.
We found that beta-actinin isoforms are present in various types of tissues in adult chicken by using immunoblotting after two dimensional gel electrophoresis; for this purpose, an antibody was raised against beta-actinin purified from adult chicken breast muscle (pectoralis major). One of the beta-actinin subunits, beta I, was present in all tissues we examined, i.e. skeletal (pectoralis major, semitendinosus, and anterior latissimus dorsi), cardiac, and smooth (gizzard) muscles, non-muscle (brain, liver, and kidney) tissues and blood, whereas another subunit, beta II, was present only in muscle tissues. A new subunit (designated beta III) that was found in the embryonic stages of skeletal muscle (Asami, Funatsu & Ishiwata (1988) J. Biochem. 103, 72-75) was present instead of beta II in non-muscle tissues and blood. In cardiac and smooth muscles, beta III coexisted with beta I and beta II. The antibody of beta-actinin did not cross-react to cytoplasmic beta-actinin (molecular weight, 80,000 daltons) found in kidney. It was suggested that the combination of beta I and beta III present in non-muscle tissues and blood is identical to the barbed end capping protein isolated from brain by Killiman and Isenberg (EMBO J. 1, 889-894 (1982)). It is likely that beta-actinin forms a genetic family whose constituents have an ability to cap either the pointed or barbed end of actin filaments.
Asami
Y
Y
Department of Physics, School of Science and Engineering, Waseda University, Tokyo.
Funatsu
T
T
Ishiwata
S
S
D000185:Actinin / Q000032:analysis*; D000818:Animals; D001842:Bone and Bones / Q000032:analysis; D001923:Brain Chemistry; D002645:Chickens; D007668:Kidney / Q000032:analysis; D009130:Muscle, Smooth / Q000032:analysis; D009132:Muscles / Q000032:analysis*; D009206:Myocardium / Q000032:analysis
D000185:Actinin