Journal article
Proinsulin and somatostatin from the islet organ of the southern-hemisphere lamprey Geotria australis
General and Comparative Endocrinology, Vol.100(3), pp.413-422
1995
Abstract
An extract of the islet organ of the southern-hemisphere lamprey Geotria australis contained a high concentration of somatostatin like immunoreactivity (34 nmol/g) but only trace amounts of insulin-like immunoreactivity. The primary structure of Geotria somatostatin-33 (AVQEAGGAAM10PPPGQRDRKA20 GCKNFFWKTF30SSC) shows almost no similarity to somatostatins from the holarctic lampreys Petromyzon marinus and Lampetra fluviatilis in the N-terminal region but the functionally important C-terminal region, including the substitution Thr31 → Ser, is the same. Insulin was not identified in the extract but proinsulin and an incompletely processed form with an intact A-chain/C-peptide junction were purified and partially characterized. The primary structure of the insulin region of Geotria proinsulin was established as A-chain; GIVEKCCHNR10CSIYQ MESYC20N; B-chain: SALTGSGGNY10LCGSYLVDAL20YLACGPRGFF30YTSTPV. This sequence contains 17 amino acid substitutions compared with the identical insulins from P. marinus and L. fluviatilis but the unusual extension to the N-terminus of the B-chain (SALTG) is present. Compared with mammalian insulins, Geotria insulin contains several substitutions of strongly conserved residues such as GinA5 → Lys in the putative receptor-binding region, GluB26 → Pro important in dimerization, and LeuA13 → Ile, HisB10 → Tyr, and HisB21 → Tyr important in hexamerization. Geotria proinsulin contains an Arg-Arg processing site at the B-chain/C-peptide junction but we speculate either that the Lys-Arg processing site at the C-peptide/A-chain junction is absent or that the Geotria pancreas is unable to synthesize a SPC2-type prohormone convertase. Our results are consistent with the view that G. australis and holarctic lampreys arose from a common stock but have been separated for a considerable period.
Details
- Title
- Proinsulin and somatostatin from the islet organ of the southern-hemisphere lamprey Geotria australis
- Authors/Creators
- J.M. Conlon (Author/Creator) - Creighton UniversityP.F. Nielsen (Author/Creator)J.H. Youson (Author/Creator)I.C. Potter (Author/Creator)
- Publication Details
- General and Comparative Endocrinology, Vol.100(3), pp.413-422
- Publisher
- Academic Press Inc.
- Identifiers
- 991005545216707891
- Copyright
- © 1995 Academic Press
- Murdoch Affiliation
- School of Biological and Environmental Sciences
- Language
- English
- Resource Type
- Journal article
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Metrics
25 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Industry collaboration
- Domestic collaboration
- International collaboration
- Citation topics
- 1 Clinical & Life Sciences
- 1.195 Neuroendocrine & Intestinal Disorders
- 1.195.565 Neuroendocrine Tumors
- Web Of Science research areas
- Endocrinology & Metabolism
- Zoology
- ESI research areas
- Biology & Biochemistry