TY - JOUR
T1 - Acetylcholinesterase clustering at the neuromuscular junction involves perlecan and dystroglycan
AU - Peng, H. Benjamin
AU - Xie, Hongbo
AU - Rossi, Susanna G.
AU - Rotundo, Richard L.
PY - 1999/5/17
Y1 - 1999/5/17
N2 - Formation of the synaptic basal lamina at vertebrate neuromuscular junction involves the accumulation of numerous specialized extracellular matrix molecules including a specific form of acetylcholinesterase (ACHE), the collagenic-tailed form. The mechanisms responsible for its localization at sites of nerve-muscle contact are not well understood. To understand synaptic AChE localization, we synthesized a fluorescent conjugate of fasciculin 2, a snake α-neurotoxin that tightly binds to the catalytic subunit. Prelabeling AChE on the surface of Xenopus muscle cells revealed that preexisting AChE molecules could be recruited to form clusters that colocalize with acetylcholine receptors at sites of nerve-muscle contact. Likewise, purified avian AChE with collagen-like tail, when transplanted to Xenopus muscle cells before the addition of nerves, also accumulated at sites of nerve-muscle contact. Using exogenous avian AChE as a marker, we show that the collagenic-tailed form of the enzyme binds to the heparan-sulfate proteoglycan perlecan, which in turn binds to the dystroglycan complex through α-dystroglycan. Therefore, the dystroglycan-perlecan complex serves as a cell surface acceptor for ACHE, enabling it to be clustered at the synapse by lateral migration within the plane of the membrane. A similar mechanism may underlie the initial formation of all specialized basal lamina interposed between other cell types.
AB - Formation of the synaptic basal lamina at vertebrate neuromuscular junction involves the accumulation of numerous specialized extracellular matrix molecules including a specific form of acetylcholinesterase (ACHE), the collagenic-tailed form. The mechanisms responsible for its localization at sites of nerve-muscle contact are not well understood. To understand synaptic AChE localization, we synthesized a fluorescent conjugate of fasciculin 2, a snake α-neurotoxin that tightly binds to the catalytic subunit. Prelabeling AChE on the surface of Xenopus muscle cells revealed that preexisting AChE molecules could be recruited to form clusters that colocalize with acetylcholine receptors at sites of nerve-muscle contact. Likewise, purified avian AChE with collagen-like tail, when transplanted to Xenopus muscle cells before the addition of nerves, also accumulated at sites of nerve-muscle contact. Using exogenous avian AChE as a marker, we show that the collagenic-tailed form of the enzyme binds to the heparan-sulfate proteoglycan perlecan, which in turn binds to the dystroglycan complex through α-dystroglycan. Therefore, the dystroglycan-perlecan complex serves as a cell surface acceptor for ACHE, enabling it to be clustered at the synapse by lateral migration within the plane of the membrane. A similar mechanism may underlie the initial formation of all specialized basal lamina interposed between other cell types.
KW - Acetylcholinesterase (ACHE)
KW - Basal lamina
KW - Dystroglycan
KW - Heparan- sulfate proteoglycan
KW - Neuromuscular junction
KW - Perlecan
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U2 - 10.1083/jcb.145.4.911
DO - 10.1083/jcb.145.4.911
M3 - Article
C2 - 10330416
AN - SCOPUS:0033577899
VL - 145
SP - 911
EP - 921
JO - Journal of Cell Biology
JF - Journal of Cell Biology
SN - 0021-9525
IS - 4
ER -