Proinsulin cDNAs from the leopard frog, Rana pipiens: evolution of proinsulin processing
| Autor: | Prashanth Sivarajah, David M. Irwin |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Amphibian
medicine.medical_specialty Physiology Molecular Sequence Data Xenopus Biochemistry Amphibians Residue (chemistry) Internal medicine biology.animal Complementary DNA medicine Animals Humans Amino Acid Sequence Molecular Biology Peptide sequence Proinsulin chemistry.chemical_classification Base Sequence C-Peptide biology Rana pipiens Leopard frog biology.organism_classification Amino acid Protein Subunits Endocrinology Amino Acid Substitution chemistry Protein Processing Post-Translational Sequence Alignment |
| Zdroj: | Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. 125:405-410 |
| ISSN: | 1096-4959 |
| Popis: | We have isolated a proinsulin cDNA from the Amphibian Rana pipiens. The predicted R. pipiens insulin A- and B-chain amino acid sequences differ from that deduced from the closely related Rana catesbeiana at one residue (Asp for Pro at B2). The R. pipiens and Xenopus laevis proinsulin precursor sequences are of identical length, with the amino acid sequences of the mature A- and B-chains being well conserved. The proinsulin C-peptide amino acid sequence is less well conserved between R. pipiens and X. laevis and also differs in length. The R. pipiens C-peptide is shorter than the homologous X. laevis sequence due to a two amino acid residue truncation. The truncation of the R. pipiens C-peptide compensates for a two amino acid residue extension observed at the N-terminal of the A-chains of insulins from Ranid frogs. A change in the site of proinsulin processing can explain both the C-peptide and A-chain length differences. The evolution of the new proinsulin processing site required two amino acid substitutions. |
| Databáze: | OpenAIRE |
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