Fig. 10. The putative first steps of myofibrillogenesis. (1) N-RAP binds to a membrane-associated complex containing ß-integrin, talin and vinculin. (2) Z-line proteins are recruited to the complex. (3) Actin polymerizes along the N-RAP super repeats, with the barbed end of the actin filament integrating with the Z-line components. The orientation of the actin filament is indicated by an arrowhead at the pointed end. (4) Post-translational modification of the N-RAP LIM domain accompanies release of the premyofibril complex from the membrane. (5) The Z-bodies fuse laterally to form Z-lines, and the modified N-RAP is removed.