Characterization of an insect heterodimeric voltage-gated sodium channel with unique alternative splicing mode.
Recent discovery of the heterodimeric voltage-gated sodium channels (Nav) in two aphid species, Acyrthosiphon pisum and Myzus persicae, aroused interest in exploring whether this kind of channel is conserved for aphids. Herewith, we aim to provide evidence for the conservation of heterodimeric Navs in aphids and investigate whether they have unique splicing patterns. We found that the only identifiable Navfrom Toxoptera citricida consisted of two subunits, forming a heterodimeric Nav, which carried an atypical "DENS" ion selectivity filter and a conventional "MFM" inactivation gate, confirming the heterodimeric Navs' conservation within aphids. These unique heterodimeric channels may form a new Navsubfamily, specific to aphids. A more ancient member of four-domain Navhomolog was well preserved in T. citricida, carrying a typical "DEEA" and "MFL" motif. The presence of "DENS" in mammalian Naxs and "DEKT" in a fungus Navsuggested that the heterodimeric Navs may still preserve Na+permeability. Sequencing 46 clones from nymphs and adults exposed unique splicing patterns for this heterodimeric Navfrom T. citricida, revealing 7 alternatively spliced exons, evidencing that exon 5 was no longer unique to Bombyx mori, and exon k/l was semi-mutually exclusive. Two previously undescribed optional exons and a SNP site seemingly unique to aphids were identified. In conclusion, the dimeric Navs might form a new aphids-specific heterodimeric Nav subfamily. This dimeric Navfrom T. citricida was characterized with distinguishable alternative splicing modes, exemplified by the discovery of two novel alternative exons and unique usage patterns of alternative exons.
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, PR China.
Xuan-Zhao
XZ
Jiang
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, PR China.
Yu-Xia
YX
Pei
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, PR China.
Wei
W
Lei
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, PR China.
Ke-Yi
KY
Wang
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, PR China.
Feng
F
Shang
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, PR China.
Hong-Bo
HB
Jiang
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, PR China. Electronic address: wangjinjun@swu.edu.cn.
Jin-Jun
JJ
Wang
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001042:Aphids / Q000235:genetics*; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D005786:Gene Expression Regulation; D023281:Genomics; D019476:Insect Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D061566:Voltage-Gated Sodium Channels / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
D019476:Insect Proteins; D012333:RNA, Messenger; D061566:Voltage-Gated Sodium Channels
Alternative splicing; Aphids; Heterodimer; Toxoptera citricida; Voltage-gated sodium channel