Immunohistochemical analysis of C-protein isoforms in cardiac and skeletal muscle of the axolotl, Ambystoma mexicanum.
Of the several proteins located within sarcomeric A-bands, C-protein, a myosin binding protein (MyBP) is thought to regulate and stabilize thick filaments during assembly. This paper reports the characterization of C-protein isoforms in juvenile and adult axolotls, Ambystoma mexicanum, by means of immunofluorescent microscopy and Western blot analyses. C-protein and myosin are found specifically within the A-bands, whereas tropomyosin and alpha-actin are detected in the I-bands of axolotl myofibrils. The MF1 antibody prepared against the fast skeletal muscle isoform of chicken C-protein specifically recognizes a cardiac isoform (Axcard1) in juvenile and adult axolotls but does not label axolotl skeletal muscle. The ALD66 antibody, which reacts with the C-protein slow isoform in chicken, local- izes only in skeletal muscle of the axolotl. This slow axolotl isoform (Axslow) displays a heterogeneous distribution in fibers of dorsalis trunci skeletal muscle. The C315 antibody against the chicken C-protein cardiac isoform identifies a second axolotl cardiac isoform (Axcard2), which is present also in axolotl skeletal muscle. No C-protein was detected in smooth muscle of the juvenile and adult axolotl with these antibodies.
Ward
S M
SM
Department of Anatomy and Cell Biology, SUNY Health Science Center at Syracuse, 750 East Adams Street, Syracuse, NY 13210, USA.
Fransen
M E
ME
Dube
D K
DK
Fischman
D A
DA
Lemanski
L F
LF
D000199:Actins / Q000378:metabolism; D000558:Ambystoma mexicanum; D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002352:Carrier Proteins; D006352:Heart Ventricles / Q000378:metabolism* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism; D012518:Sarcomeres / Q000378:metabolism; D014335:Tropomyosin / Q000378:metabolism; D000099163:Myosin Binding Protein C
D000199:Actins; D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D009124:Muscle Proteins; D009218:Myosins; D014335:Tropomyosin; D000099163:Myosin Binding Protein C