Intron retention as a posttranscriptional regulatory mechanism of neurotoxin expression at early life stages of the starlet anemone Nematostella vectensis.
Sea anemones use an arsenal of peptide neurotoxins accumulated in special stinging cells (nematocytes) for defense and predation. Intriguingly, genomic analysis of Nematostella vectensis revealed only a single toxin, Nv1 (N. vectensis toxin 1), encoded by multiple extremely conserved genes. We examined the toxic potential of Nv1 and whether it is produced by the three developmental stages (embryo, planula, and polyp) of Nematostella. Nv1 was expressed in recombinant form and, similarly to Type I sea anemone toxins, inhibited the inactivation of voltage-gated sodium channels. However, in contrast to the other toxins, Nv1 revealed high specificity for insect over mammalian voltage-gated sodium channels. Transcript analysis indicated that multiple Nv1 loci are transcribed at all developmental stages of N. vectensis, whereas splicing of these transcripts is restricted to the polyp stage. This finding suggests that regulation of Nv1 synthesis is posttranscriptional and that the embryo and planula stages do not produce the Nv1 toxin. This rare phenomenon of intron retention at the early developmental stages is intriguing and raises the question as to the mechanism enabling such differential expression in sea anemones.
Department of Plant Sciences, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel. moranyeh@post.tau.ac.il
Yehu
Y
Moran
Hagar
H
Weinberger
Adam M
AM
Reitzel
James C
JC
Sullivan
Roy
R
Kahn
Dalia
D
Gordon
John R
JR
Finnerty
Michael
M
Gurevitz
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D019295:Computational Biology / Q000379:methods; D004220:Disulfides / Q000737:chemistry; D004625:Embryo, Nonmammalian; D004926:Escherichia coli / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D006639:Histidine / Q000378:metabolism; D007438:Introns; D008018:Life Cycle Stages; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012615:Sea Anemones / Q000196:embryology / Q000235:genetics* / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D004220:Disulfides; D009498:Neurotoxins; D011994:Recombinant Proteins; D006639:Histidine