The tetrameric globular form of acetylcholinesterase (G(4) AChE) is present and precisely controlled in muscles. The assembly and membrane targeting of G(4) AChE are directed by a proline-rich membrane anchor (PRiMA). It has been demonstrated that in muscle cells, the expression of PRiMA mRNA, as well as the level of G(4) AChE was suppressed by myogenesis and innervating nerve. A human PRiMA promoter-driven luciferase reporter was employed in this study to further reveal the activity of PRiMA transcription during myogenic differentiation and the influence of innervation. In parallel with PRiMA mRNA, the PRiMA promoter activity was suppressed by both myogenic regulatory factor(s) (MRFs) and nerve-derived factor(s). These results suggest that the regulation of PRiMA mRNA expression in muscle by MRFs and nerve-derived factors is due to a control system at the transcriptional level.