| The development of the myofibrillar apparatus in skeletal muscle is a process in which transmembrane linkages with adhesion molecules are implicated. Integrins are one class of transmembrane adhesion receptors which appear to mediate these interactions. Two prominent linkages are at the myotendinous junction (MTJ), which resides at the ends of the cell and connects myofibrils to the tendon, and the costameres, which encircle the Z-disks and link the sarcomere to the sarcolemma. In this study we report that the ;We have also isolated a monoclonal antibody, P4B2, which localizes to multiple adhesion junctions, namely, a subset of focal adhesions, the Z-disc of muscle, and neuromuscular junctions. Immunopurification of the antigen to this antibody from chicken brain tissue yielded a complex of three prominent proteins with mobilities of 36, 30 and 18 kD. Amino acid sequencing of the purified proteins identified the 36 kD protein as GAPDH. The other 2 protein bands were heterogeneous, containing proteins found in the synaptic vesicle fusion core complex. Immunolocalization of P4B2 antigen in developing cultured muscle cells showed that the antigen is incorporated into Z-lines soon after the sarcomeric architecture was positive for... |
