• Roy C Y Choi, Vicky P Chen, Wilson K W Luk, Amanda W Y Yung, Alice H M Ng, Tina T X Dong, and Karl W K Tsim.
• Division of Life Science, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, SAR. roychoi@ust.hk
• Chem. Biol. Interact. 2013 Mar 25; 203 (1): 282-6.

AbstractThe gene encoding the collagen-tailed subunit (ColQ) of acetylcholinesterase (AChE) contains two distinct promoters that drive the production of two ColQ mRNAs, ColQ-1 and ColQ-1a, in slow- and fast-twitch muscles, respectively. ColQ-1a is expressed at the neuromuscular junction (NMJ) in fast-twitch muscle, and this expression depends on trophic factors supplied by motor neurons signaling via a cAMP-dependent pathway in muscle. To further elucidate the molecular basis of ColQ-1a's synaptic expression, here we investigated the expression and localization of cAMP-responsive element binding protein (CREB) at the synaptic and extra-synaptic regions of fast- and slow-twitch muscles from adult rats. The total amount of active, phosphorylated CREB (P-CREB) present in slow-twitch soleus muscle was higher than that in fast-twitch tibialis muscle, but P-CREB was predominantly expressed in the fast-twitch muscle at NMJs. In contrast, P-CREB was detected in both synaptic and extra-synaptic regions of slow-twitch muscle. These results reveal, for the first time, the differential distribution of P-CREB in fast- and slow-twitch muscles, which might support the crucial role of cAMP-dependent signaling in controlling the synapse-specific expression of ColQ-1a in fast-twitch muscles.Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

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