TY - JOUR
T1 - Diversity of voltage-gated sodium channels in the ascidian larval nervous system
AU - Nagahora, Hitoshi
AU - Okada, Toshiaki
AU - Yahagi, Naoya
AU - Chong, Jayhong Andrew
AU - Mandel, Gail
AU - Okamura, Yasushi
N1 - Funding Information:
We thank Drs. K. Takahashi (Meiji College of Pharmacy) and H. Okamoto (National Institute of Bioscience and Human-Technology) for continuous support. This work was partially supported by a Research Grant from Human Frontier Science Program (Y.O. and G.M.) and NIH grant NS 22518 to G.M. Gene Accession No. for TuNa2 is AB042806.
PY - 2000/8/28
Y1 - 2000/8/28
N2 - To gain insight into the origin of the molecular diversity of voltage-gated sodium channels (NaVs), a putative sodium channel gene (TuNa2) was cloned from the protochordate ascidian. TuNa2 showed two unusual features in its primary structure; (1) lysine in the P-region of the third repeat, a critical site determining ion selectivity, was changed to glutamic acid, predicting that the ionic permeability would not be rigidly sodium-selective (2) the III-IV linker, determinant of fast inactivation, was only weakly conserved. In contrast with a pan-neuronally expressed NaV (TuNa1), expression of TuNa2 was confined to subsets of neurons including motor neurons, suggesting that TuNa2 plays specialized roles in electrical activities unique to these neurons. Basic FGF, a neural inducer in the ascidian embryo, induces TuNa2 RNA expression in the ectodermal cells at lower doses than that required for TuNa1 gene expression. Thus, two types of NaV may play distinct roles and their gene expressions are controlled by distinct mechanisms. (C) 2000 Academic Press.
AB - To gain insight into the origin of the molecular diversity of voltage-gated sodium channels (NaVs), a putative sodium channel gene (TuNa2) was cloned from the protochordate ascidian. TuNa2 showed two unusual features in its primary structure; (1) lysine in the P-region of the third repeat, a critical site determining ion selectivity, was changed to glutamic acid, predicting that the ionic permeability would not be rigidly sodium-selective (2) the III-IV linker, determinant of fast inactivation, was only weakly conserved. In contrast with a pan-neuronally expressed NaV (TuNa1), expression of TuNa2 was confined to subsets of neurons including motor neurons, suggesting that TuNa2 plays specialized roles in electrical activities unique to these neurons. Basic FGF, a neural inducer in the ascidian embryo, induces TuNa2 RNA expression in the ectodermal cells at lower doses than that required for TuNa1 gene expression. Thus, two types of NaV may play distinct roles and their gene expressions are controlled by distinct mechanisms. (C) 2000 Academic Press.
KW - Ascidian
KW - Ion selectivity
KW - Motor neuron
KW - Sodium channel
KW - bFGF
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U2 - 10.1006/bbrc.2000.3290
DO - 10.1006/bbrc.2000.3290
M3 - Article
C2 - 10964703
AN - SCOPUS:0034726712
SN - 0006-291X
VL - 275
SP - 558
EP - 564
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -