Meeting Abstract
P1.179 Friday, Jan. 4 Cloning and Expression Study of the Five Pandalopsis japonica (the Morotoge shrimp) Nicotinic Acetylcholine Receptor Subunits KIM, G.R; PuKyung National University, Republic of Korea arctickkl@pknu.ac.kr
The Nicotinic Acetylcholine Receptor (nAChR) is a diverse family of neurotransmitter-gated ion channels which contain five transmembrane subunits arranged around a central pore. It mediates synaptic transmission at the junction between nerve and muscle cell. It is also involved in several neurological pathologies. The basic linear sequence of all nAChR subunits appears as a large extracellular domain, four transmembrane domains, and a cytoplasmic domain of variable size that resides between transmembrane domain 3 and 4 (TM3 and TM4). Subunits are classified by the presence of two adjacent cysteines in c-loop which are important for acetylcholine binding. A Cys-Cys pair is identified only α-subunits. Compared with vertebrate, relatively less has been studied about the invertebrate nAChR, especially Crustacean’s nAChRs. This study will help an understanding of Crustacean’s nAChRs. Pandalopsis japonica (morotoge shrimp) is one of the important shrimp in East Asian countries, including Korea and Japan. From the previous Expressed Sequence Tag (EST) project, we identified 5 subunits that display a high sequence similarity to nAChR subunits. 4 alpha subunits, 1 beta subunit were confirmed by RACE and PCR sequencing. Phylogenetic analysis by amino sequence revealed that one alpha 4(Paj-α4), one beta 1(Paj-β1) and three divergent (Paj-α10~12) subunits are classified. Compare with insects, all subunits were much conserved. And Paj-α4 has three variants. This variants site was located between TM3 and TM4. More study is needed on this site. Attempts to express functional native nAChR consisting of Paj-α4, β1, α10~12 in Xenopus laevis oocytes were not expressed. Only Paj-β1 was heterologously expressed with Rα4 (Rattus norvegicus α-4 subunit). We report for the first time a heterologous functional nAChR consisting with invertebrate beta subunit.
