Expression and Localization of PRiMA-Linked Globular Form Acetylcholinesterase in Vertebrate Neuromuscular Junctions
- 198 Downloads
Acetylcholinesterase (AChE) is well known to process different molecular forms via the distinct interacting partners. Proline-rich membrane anchor (PRiMA)-linked tetrameric globular AChE (G4 AChE) is mainly found in the vertebrate brain; however, recent studies from our laboratory have suggested its existence at neuromuscular junctions (nmjs). Both muscle and motor neuron express AChE at the nmjs. In muscle, the expression of PRiMA-linked AChE is down-regulated during myogenic differentiation and by motor neuron innervation. As compared with muscle, spinal cord possessed higher total AChE activity and contained PRiMA-linked AChE forms. The spinal cord expression of this form increased during development. More importantly, PRiMA-linked G4 AChE identified as aggregates localized at nmjs. These findings suggest that the restricted localization of PRiMA-linked G4 AChE at the nmjs could be contributed by the pre-synaptic motor neuron and/or the post-synaptic muscle fiber.
KeywordsAChE PRiMA G4 AChE Muscle Spinal cord Neuromuscular junctions
The research was supported by grants from Research Grants Council (HKUST6419/06M, 662407, 662608, and N_HKUST629/07) of the Hong Kong SAR to KWKT.
- Jiang, J. X. S., Choi, R. C. Y., Siow, N. L., Lee, H. H. C., Wan, D. C. C., & Tsim, K. W. K. (2003). Muscle induces neuronal expression of acetylcholinesterase in neuron-muscle co-culture: Transcriptional regulation mediated by cAMP-dependent signaling. Journal of Biological Chemistry, 278, 45435–45444.CrossRefPubMedGoogle Scholar
- Lee, H. H., Choi, R. C., Ting, A. K., Siow, N. L., Jiang, J. X., Massoulié, J., et al. (2004). Transcriptional regulation of acetylcholinesterase-associated collagen ColQ: Differential expression in fast and slow twitch muscle fibers is driven by distinct promoters. Journal of Biological Chemistry, 279, 27098–27107.CrossRefPubMedGoogle Scholar
- Leung, K. W., Xie, H. Q., Chen, V. P., Mok, M. K. W., Chu, G. K. Y., Choi, R. C. Y., et al. (2009). Restricted localization of proline-rich membrane anchor (PRiMA) of globular form acetylcholinesterase at the neuromuscular junctions: Contribution and expression from motor neurons. FEBS J, 276, 3031–3042.CrossRefPubMedGoogle Scholar
- Xie, H. Q., Choi, R. C. Y., Leung, K. W., Siow, N. L., Kong, L. W., Lau, F. T. C., et al. (2007). Regulation of a transcript encoding the proline-rich membrane anchor of globular muscle acatelycholinesterase. The suppressive roles of myogenesis and innervating nerves. Journal of Biological Chemistry, 282, 11765–11775.CrossRefPubMedGoogle Scholar
- Xie, H. Q., Choi, R. C. Y., Leung, W. K. W., Chen, V. P., Chu, G. K. Y., & Tsim, K. W. K. (2009). Transcriptional regulation of proline-rich membrane anchor (PRiMA) of globular form acetylcholinesterase in neuron: An inductive effect of neuron differentiation. Brain Res, 1265, 13–23.CrossRefPubMedGoogle Scholar