Neuromuscular Junction (NMJ): Acetylcholinesterases

Acetylcholinesterase (AChE) molecules are attached to the synaptic basal lamina in between the nerve terminal and the receptor-rich postsynaptic membrane. Their function is to terminate neurotransmission by rapidly hydrolyzing acetylcholine released by the motor neurons. Expression of AChE at the neuromuscular synapse has been studied for more than 70. years as a marker for nerve-muscle interactions and was the first synapse-specific protein identified. The AChE molecules are synthesized by the skeletal muscle fibers in a very small region of the sarcoplasm underlying the nerve terminal containing the subsynaptic nuclei. This enzyme is regulated at the transcriptional, translational and posttranslational levels, including assembly with noncatalytic subunits that target it to the synaptic region where it remains attached to the synaptic basal lamina.