Three insulin-relaxin-like genes in Ciona intestinalis
2006 (English)In: Peptides, ISSN 0196-9781, E-ISSN 1873-5169, Vol. 27, no 11, 2535-2546 p.Article in journal (Refereed) Published
The Ciona intestinalis genome harbors three insulin-like genes: INS-L1, -L2 and -L3. Conserved synteny between the Ciona-human genomes predicts that Ciona INS-Ls are orthologous to the vertebrate insulin-relaxin family, but this relation cannot be inferred from molecular phylogeny. A conserved protein core with six cysteines; typical arrangement of B-, C- and A-protein domains; pro-protein maturation mode; and putative insulin receptor-binding sites were identified in Ciona INS-L proteins. ESTs used to assemble exonic sequences of INS-Ls combined with qRT-PCR analysis provided evidence that the predicted genes are expressed in the developing and adult Ciona. Our results support that Ciona INS-L1 is orthologous to the vertebrate insulin-like/relaxin genes, INS-L2 to insulin genies and INS-L3 to IGF genes. Our analysis also implies that the insulin-like/relaxin ancestor switched receptor type from tyrosine kinase- to GPCR-type, whereas insulin-IGF subfamily retained the tyrosine kinase-type of receptor. We propose that this receptor-switch occurred after the time when urochordates branched from the common chordate lineage, but before the two genome-duplications at the root of the vertebrates.
Place, publisher, year, edition, pages
2006. Vol. 27, no 11, 2535-2546 p.
Ciona intestinalis, gene duplication, IGF, insulin, insulin-like protein, relaxin
Medical and Health Sciences Biological Sciences
IdentifiersURN: urn:nbn:se:uu:diva-95914DOI: 10.1016/j.peptides.2006.06.008ISI: 000242318900001PubMedID: 16920224OAI: oai:DiVA.org:uu-95914DiVA: diva2:170291