1
|
Irwin DM. Variation in the rates of evolution of the insulin and glucagon hormone and receptor genes in rodents. Gene 2020; 728:144296. [DOI: 10.1016/j.gene.2019.144296] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/13/2019] [Accepted: 12/13/2019] [Indexed: 02/07/2023]
|
2
|
Abstract
Freeze tolerance is an amazing winter survival strategy used by various amphibians and reptiles living in seasonally cold environments. These animals may spend weeks or months with up to ∼65% of their total body water frozen as extracellular ice and no physiological vital signs, and yet after thawing they return to normal life within a few hours. Two main principles of animal freeze tolerance have received much attention: the production of high concentrations of organic osmolytes (glucose, glycerol, urea among amphibians) that protect the intracellular environment, and the control of ice within the body (the first putative ice-binding protein in a frog was recently identified), but many other strategies of biochemical adaptation also contribute to freezing survival. Discussed herein are recent advances in our understanding of amphibian and reptile freeze tolerance with a focus on cell preservation strategies (chaperones, antioxidants, damage defense mechanisms), membrane transporters for water and cryoprotectants, energy metabolism, gene/protein adaptations, and the regulatory control of freeze-responsive hypometabolism at multiple levels (epigenetic regulation of DNA, microRNA action, cell signaling and transcription factor regulation, cell cycle control, and anti-apoptosis). All are providing a much more complete picture of life in the frozen state.
Collapse
Affiliation(s)
| | - Janet M. Storey
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| |
Collapse
|
3
|
Tsend-Ayush E, He C, Myers MA, Andrikopoulos S, Wong N, Sexton PM, Wootten D, Forbes BE, Grutzner F. Monotreme glucagon-like peptide-1 in venom and gut: one gene - two very different functions. Sci Rep 2016; 6:37744. [PMID: 27898108 PMCID: PMC5127184 DOI: 10.1038/srep37744] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 11/01/2016] [Indexed: 12/11/2022] Open
Abstract
The importance of Glucagon like peptide 1 (GLP-1) for metabolic control and insulin release sparked the evolution of genes mimicking GLP-1 action in venomous species (e.g. Exendin-4 in Heloderma suspectum (gila monster)). We discovered that platypus and echidna express a single GLP-1 peptide in both intestine and venom. Specific changes in GLP-1 of monotreme mammals result in resistance to DPP-4 cleavage which is also observed in the GLP-1 like Exendin-4 expressed in Heloderma venom. Remarkably we discovered that monotremes evolved an alternative mechanism to degrade GLP-1. We also show that monotreme GLP-1 stimulates insulin release in cultured rodent islets, but surprisingly shows low receptor affinity and bias toward Erk signaling. We propose that these changes in monotreme GLP-1 are the result of conflicting function of this peptide in metabolic control and venom. This evolutionary path is fundamentally different from the generally accepted idea that conflicting functions in a single gene favour duplication and diversification, as is the case for Exendin-4 in gila monster. This provides novel insight into the remarkably different metabolic control mechanism and venom function in monotremes and an unique example of how different selective pressures act upon a single gene in the absence of gene duplication.
Collapse
Affiliation(s)
- Enkhjargal Tsend-Ayush
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia
| | - Chuan He
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia
| | - Mark A Myers
- School of Applied and Biomedical Sciences, Federation University Australia, Mount Helen, Victoria, 3353, Australia
| | - Sof Andrikopoulos
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Nicole Wong
- Department of Medicine, Austin Health, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Patrick M Sexton
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, 3052, Australia
| | - Denise Wootten
- Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, 3052, Australia
| | - Briony E Forbes
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia.,School of Medicine, Flinders University, Bedford Park, South Australia, 5042, Australia
| | - Frank Grutzner
- Robinson Research Institute, School of Biological Sciences, The University of Adelaide, South Australia, 5000, Australia
| |
Collapse
|
4
|
Kosinová L, Veverka V, Novotná P, Collinsová M, Urbanová M, Moody NR, Turkenburg JP, Jiráček J, Brzozowski AM, Žáková L. Insight into the structural and biological relevance of the T/R transition of the N-terminus of the B-chain in human insulin. Biochemistry 2014; 53:3392-402. [PMID: 24819248 PMCID: PMC4047818 DOI: 10.1021/bi500073z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
![]()
The N-terminus of the B-chain of
insulin may adopt two alternative
conformations designated as the T- and R-states. Despite the recent
structural insight into insulin–insulin receptor (IR) complexes,
the physiological relevance of the T/R transition is still unclear.
Hence, this study focused on the rational design, synthesis, and characterization
of human insulin analogues structurally locked in expected R- or T-states.
Sites B3, B5, and B8, capable of affecting the conformation of the
N-terminus of the B-chain, were subjects of rational substitutions
with amino acids with specific allowed and disallowed dihedral φ
and ψ main-chain angles. α-Aminoisobutyric acid was systematically
incorporated into positions B3, B5, and B8 for stabilization of the
R-state, and N-methylalanine and d-proline
amino acids were introduced at position B8 for stabilization of the
T-state. IR affinities of the analogues were compared and correlated
with their T/R transition ability and analyzed against their crystal
and nuclear magnetic resonance structures. Our data revealed that
(i) the T-like state is indeed important for the folding efficiency
of (pro)insulin, (ii) the R-state is most probably incompatible with
an active form of insulin, (iii) the R-state cannot be induced or
stabilized by a single substitution at a specific site, and (iv) the
B1–B8 segment is capable of folding into a variety of low-affinity
T-like states. Therefore, we conclude that the active conformation
of the N-terminus of the B-chain must be different from the “classical”
T-state and that a substantial flexibility of the B1–B8 segment,
where GlyB8 plays a key role, is a crucial prerequisite for an efficient
insulin–IR interaction.
Collapse
Affiliation(s)
- Lucie Kosinová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , v.v.i., Flemingovo nám 2, 166 10 Prague 6, Czech Republic
| | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Nei M, Suzuki Y, Nozawa M. The neutral theory of molecular evolution in the genomic era. Annu Rev Genomics Hum Genet 2010; 11:265-89. [PMID: 20565254 DOI: 10.1146/annurev-genom-082908-150129] [Citation(s) in RCA: 162] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The neutral theory of molecular evolution has been widely accepted and is the guiding principle for studying evolutionary genomics and the molecular basis of phenotypic evolution. Recent data on genomic evolution are generally consistent with the neutral theory. However, many recently published papers claim the detection of positive Darwinian selection via the use of new statistical methods. Examination of these methods has shown that their theoretical bases are not well established and often result in high rates of false-positive and false-negative results. When the deficiencies of these statistical methods are rectified, the results become largely consistent with the neutral theory. At present, genome-wide analyses of natural selection consist of collections of single-locus analyses. However, because phenotypic evolution is controlled by the interaction of many genes, the study of natural selection ought to take such interactions into account. Experimental studies of evolution will also be crucial.
Collapse
Affiliation(s)
- Masatoshi Nei
- Institute of Molecular Evolutionary Genetics and Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.
| | | | | |
Collapse
|
6
|
Vera F, Zenuto RR, Antenucci CD. Decreased glucose tolerance but normal blood glucose levels in the field in the caviomorph rodent Ctenomys talarum: The role of stress and physical activity. Comp Biochem Physiol A Mol Integr Physiol 2008; 151:232-8. [DOI: 10.1016/j.cbpa.2008.06.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 06/26/2008] [Accepted: 06/26/2008] [Indexed: 12/31/2022]
|
7
|
Wan ZL, Huang K, Hu SQ, Whittaker J, Weiss MA. The structure of a mutant insulin uncouples receptor binding from protein allostery. An electrostatic block to the TR transition. J Biol Chem 2008; 283:21198-210. [PMID: 18492668 PMCID: PMC2475698 DOI: 10.1074/jbc.m800235200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 05/01/2008] [Indexed: 11/06/2022] Open
Abstract
The zinc insulin hexamer undergoes allosteric reorganization among three conformational states, designated T(6), T(3)R(3)(f), and R(6). Although the free monomer in solution (the active species) resembles the classical T-state, an R-like conformational change is proposed to occur upon receptor binding. Here, we distinguish between the conformational requirements of receptor binding and the crystallographic TR transition by design of an active variant refractory to such reorganization. Our strategy exploits the contrasting environments of His(B5) in wild-type structures: on the T(6) surface but within an intersubunit crevice in R-containing hexamers. The TR transition is associated with a marked reduction in His(B5) pK(a), in turn predicting that a positive charge at this site would destabilize the R-specific crevice. Remarkably, substitution of His(B5) (conserved among eutherian mammals) by Arg (occasionally observed among other vertebrates) blocks the TR transition, as probed in solution by optical spectroscopy. Similarly, crystallization of Arg(B5)-insulin in the presence of phenol (ordinarily a potent inducer of the TR transition) yields T(6) hexamers rather than R(6) as obtained in control studies of wild-type insulin. The variant structure, determined at a resolution of 1.3A, closely resembles the wild-type T(6) hexamer. Whereas Arg(B5) is exposed on the protein surface, its side chain participates in a solvent-stabilized network of contacts similar to those involving His(B5) in wild-type T-states. The substantial receptor-binding activity of Arg(B5)-insulin (40% relative to wild type) demonstrates that the function of an insulin monomer can be uncoupled from its allosteric reorganization within zinc-stabilized hexamers.
Collapse
Affiliation(s)
- Zhu-li Wan
- Departments of Biochemistry
and Nutrition, Case Western Reserve
University School of Medicine, Cleveland, Ohio 44106
| | - Kun Huang
- Departments of Biochemistry
and Nutrition, Case Western Reserve
University School of Medicine, Cleveland, Ohio 44106
| | - Shi-Quan Hu
- Departments of Biochemistry
and Nutrition, Case Western Reserve
University School of Medicine, Cleveland, Ohio 44106
| | - Jonathan Whittaker
- Departments of Biochemistry
and Nutrition, Case Western Reserve
University School of Medicine, Cleveland, Ohio 44106
| | - Michael A. Weiss
- Departments of Biochemistry
and Nutrition, Case Western Reserve
University School of Medicine, Cleveland, Ohio 44106
| |
Collapse
|
8
|
Glendorf T, Sørensen AR, Nishimura E, Pettersson I, Kjeldsen T. Importance of the solvent-exposed residues of the insulin B chain alpha-helix for receptor binding. Biochemistry 2008; 47:4743-51. [PMID: 18376848 DOI: 10.1021/bi800054z] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conjointly, the solvent-exposed residues of the central alpha-helix of the B chain form a well-defined ridge, which is flanked and partly overlapped by the two described insulin receptor binding surfaces on either side of the insulin molecule. To evaluate the importance of this interface in insulin receptor binding, we developed a new powerful method that allows us to introduce all the naturally occurring amino acids into a given position and subsequently determine the receptor binding affinities of the resulting insulin analogues. The total amino acid scanning mutagenesis was performed at positions B9, B10, B12, B13, B16, and B17, and the vast majority of the insulin analogue precursors were expressed and secreted in amounts close to that of the wild-type (human insulin) precursor. The analogue binding data revealed that positions B12 and B16 were the two positions most affected by the amino acid substitutions. Interestingly, the receptor binding affinities of the B13 analogues were also markedly affected by the amino acid substitutions, suggesting that GluB13 indeed is a part of insulin's binding surface. The B10 library screen generated analogues covering a wide range of (20-340%) of relative binding affinities, and the results indicated that a structural stabilization of the central alpha-helix and thereby a more rigid presentation of the binding epitope at the insulin receptor is important for receptor recognition. In conclusion, systematic amino acid scanning mutagenesis allowed us to confirm the importance of the B chain alpha-helix as a central recognition element serving as a linker of a continual binding surface.
Collapse
Affiliation(s)
- Tine Glendorf
- Diabetes Protein Engineering, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Måløv, Denmark.
| | | | | | | | | |
Collapse
|
9
|
Hua QX, Liu M, Hu SQ, Jia W, Arvan P, Weiss MA. A conserved histidine in insulin is required for the foldability of human proinsulin: structure and function of an ALAB5 analog. J Biol Chem 2006; 281:24889-99. [PMID: 16728398 DOI: 10.1074/jbc.m602617200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The insulins of eutherian mammals contain histidines at positions B5 and B10. The role of His(B10) is well defined: although not required in the mature hormone for receptor binding, in the islet beta cell this side chain functions in targeting proinsulin to glucose-regulated secretory granules and provides axial zincbinding sites in storage hexamers. In contrast, the role of His(B5) is less well understood. Here, we demonstrate that its substitution with Ala markedly impairs insulin chain combination in vitro and blocks the folding and secretion of human proinsulin in a transfected mammalian cell line. The structure and stability of an Ala(B5)-insulin analog were investigated in an engineered monomer (DKP-insulin). Despite its impaired foldability, the structure of the Ala(B5) analog retains a native-like T-state conformation. At the site of substitution, interchain nuclear Overhauser effects are observed between the methyl resonance of Ala(B5) and side chains in the A chain; these nuclear Overhauser effects resemble those characteristic of His(B5) in native insulin. Substantial receptor binding activity is retained (80 +/- 10% relative to the parent monomer). Although the thermodynamic stability of the Ala(B5) analog is decreased (DeltaDeltaG(u) = 1.7 +/- 0.1 kcal/mol), consistent with loss of His(B5)-related interchain packing and hydrogen bonds, control studies suggest that this decrement cannot account for its impaired foldability. We propose that nascent long-range interactions by His(B5) facilitate alignment of Cys(A7) and Cys(B7) in protein-folding intermediates; its conservation thus reflects mechanisms of oxidative folding rather than structure-function relationships in the native state.
Collapse
Affiliation(s)
- Qing-Xin Hua
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106-4935
| | | | | | | | | | | |
Collapse
|
10
|
Opazo JC, Palma RE, Melo F, Lessa EP. Adaptive evolution of the insulin gene in caviomorph rodents. Mol Biol Evol 2005; 22:1290-8. [PMID: 15728738 DOI: 10.1093/molbev/msi117] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Insulin is a conservative molecule among mammals, maintaining both its structure and function. Rodents that belong to the Suborder Hystricognathi represent an exception, having a very divergent molecule with unusual physiological properties. In this work, we analyzed the evolutionary pattern of the insulin gene in caviomorph rodents (South American hystricomorph rodents). We found that these rodents have higher rates of nonsynonymous:synonymous substitutions (d(N)/d(S)) than nonhystricomorph rodents and that values are heterogeneous inside the group. We estimated codons under positive selection, specifically the second binding site (A13 and B17) and others related with hexamerization (B18, B20, and B22). In the monomer structure, all selected sites formed a single patch around the second binding site. In the hexamer structure, these amino acids were grouped into three major patches. In this structure, contacts between B chains involved all selected sites (except B18), and between faces in the center of the molecule, all contacts were among selected sites. While there is no clear hypothesis regarding the cause of this drastic change, experimental evidence does show that this group of rodents has some peculiarities in growth function, and, whether coincidental or not, these changes appeared together with important changes in life-history traits.
Collapse
Affiliation(s)
- Juan C Opazo
- Center for Advanced Studies in Ecology and Biodiversity, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | | | | | | |
Collapse
|
11
|
Opazo JC, Soto-Gamboa M, Bozinovic F. Blood glucose concentration in caviomorph rodents. Comp Biochem Physiol A Mol Integr Physiol 2004; 137:57-64. [PMID: 14720591 DOI: 10.1016/j.cbpb.2003.09.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Hystricomorph rodents are a group of species that belong to the suborder Hystricognathi. They mainly inhabit South American (caviomorph) and African (phiomorph) habitats. This group of rodents has a divergent insulin structure. For example, insulin in this group of rodents exhibits only 1-10% of biological activity in comparison to other mammals. Therefore, hystricomorph rodents may hypothetically be unable to regulate blood glucose concentration as non-hystricomorph mammals. In this work we evaluated blood glucose concentration in nine species of caviomorph rodents, with emphasis on species belonging to the families Abrocomidae, Ctenomyidae and Octodontidae. Specifically we: (1) measured glucose concentrations after a fasting period; and (2) conducted a glucose tolerance test. In the latter assay we used Octodon degus as a representative species of the genus Octodon. Results showed that blood glucose concentration values after fasting, and in the glucose tolerance test, were within the expected range for mammals. We postulate that this group of rodents has compensatory traits that may permit the maintenance of standard values of plasma glucose.
Collapse
Affiliation(s)
- Juan C Opazo
- Center for Advanced Studies in Ecology and Biodiversity and Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O'Higgins 340, Santiago 6513677, Chile.
| | | | | |
Collapse
|
12
|
Abstract
The conformation of insulin in the crystalline state has been known for more than 30 years but there remains uncertainty regarding the biologically active conformation and the structural features that constitute the receptor-binding domain. The primary structure of insulin has been determined for at least 100 vertebrate species. In addition to the invariant cysteines, only ten amino acids (GlyA1, IleA2, ValA3, TyrA19, LeuB6, GlyB8, LeuB11, ValB12, GlyB23 and PheB24) have been fully conserved during vertebrate evolution. This observation supports the hypothesis derived from alanine-scanning mutagenesis studies that five of these invariant residues (IleA2, ValA3, TyrA19, GlyB23, and Phe24) interact directly with the receptor and five additional conserved residues (LeuB6, GlyB8, LeuB11, GluB13 and PheB25) are important in maintaining the receptor-binding conformation. With the exception of the hagfish, only conservative substitutions are found at B13 (Glu --> Asp) and B25(Phe --> Tyr). In contrast, amino acid residues that were also considered to be important in receptor binding based upon the crystal structure of insulin (GluA4, GlnA5, AsnA21, TyrB16, TyrB26) have been much less well conserved and are probably not components of the receptor-binding domain. The hypothesis that LeuA13 and LeuB17 form part of a second receptor-binding site in the insulin molecule finds some support in terms of their conservation during vertebrate evolution, although the site is probably absent in some hystricomorph insulins. In general, the amino acid sequences of insulins are not useful in cladistic analyses especially when evolutionary distant taxa are compared but, among related species in a particular order or family, the presence of unusual structural features in the insulin molecule may permit a meaningful phylogenetic inference. For example, analysis of insulin sequences supports monophyletic status for Dipnoi, Elasmobranchii, Holocephali and Petromyzontiformes.
Collapse
Affiliation(s)
- J M Conlon
- Regulatory Peptide Center, Department of Biomedical Sciences, Creighton University Medical School, Omaha NE 68178-0405, USA.
| |
Collapse
|
13
|
Storey KB, Storey JM. Chapter 1 Signal transduction and gene expression in the regulation of natural freezing survival. CELL AND MOLECULAR RESPONSE TO STRESS 2001. [DOI: 10.1016/s1568-1254(01)80003-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
14
|
Magee BA, Shooter GK, Wallace JC, Francis GL. Insulin-like growth factor I and its binding proteins: a study of the binding interface using B-domain analogues. Biochemistry 1999; 38:15863-70. [PMID: 10625451 DOI: 10.1021/bi9910070] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The biological activity of the insulin-like growth factors (IGF-I and IGF-II) is regulated by six IGF binding proteins (IGFBPs 1-6). To examine the surface of IGF-I that associates with the IGFBPs, we created a series of six IGF-I analogues, [His(4)]-, [Gln(9)]-, [Lys(9)]-, [Ser(16)]-, [Gln(9),Ser(16)]-, and [Lys(9),Ser(16)]IGF-I, that contained substitutions for residues Thr(4), Glu(9), or Phe(16). Substitution of Ser for Phe(16) did not affect secondary structure but significantly decreased the affinity for all IGFBPs by between 14-fold and >330-fold, indicating that Phe(16) is functionally important for IGFBP association. While His(4) or Gln(9) substitutions had little effect on IGFBP affinity, changing the negative charge of Glu(9) to a positive Lys(9) selectively decreased the affinities of IGFBP-2 and -6 by 140- and 30-fold, respectively. Furthermore, the effects of mutations to both residues 9 and 16 appear to be additive. The analogues are biologically active in rat L6 myoblasts and they retain native structure as assessed by their far-UV circular dichroism (CD) profiles. We propose that Phe(16) and adjacent hydrophobic residues (Leu(5) and Leu(54)) form a functional binding pocket for IGFBP association.
Collapse
Affiliation(s)
- B A Magee
- Cooperative Research Center for Tissue Growth and Repair, Department of Biochemistry, University of Adelaide, Adelaide, South Australia 5005, Australia
| | | | | | | |
Collapse
|
15
|
Conlon JM, Fan H, Fritzsch B. Purification and structural characterization of insulin and glucagon from the bichir Polypterus senegalis (Actinopterygii: Polypteriformes). Gen Comp Endocrinol 1998; 109:86-93. [PMID: 9446726 DOI: 10.1006/gcen.1997.7007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Polypteriformes (bichirs and reedfish) are a family of ray-finned fishes of ancient lineage. Insulin has been isolated from an extract of the pancreas and upper gastrointestinal tract of the bichir Polypterus senegalis and its primary structure established as A-chain: Gly-Ile-Val-Glu-Gln-Cys-Cys-Asp-Thr-Pro10-Cys-Ser- Leu-Tyr-Asp-Leu-Glu-Asn-Tyr-Cys20-Asn: B-chain: Ala-Ala-Asn-Arg-His-Leu-Cys-Gly-Ser-His10-Leu-Val- Glu-Ala-Leu-Tyr-Leu-Val-Cys-Gly20-Asn-Arg-Gly-Phe- Phe-Tyr-Ile-Pro-Ser-Lys30-Met. Despite the fact that Polypterus insulin contains several unusual structural features that are not found in insulins from other jawed fish (Asp at A-8, Thr at A-9, Arg at B-4, Asn at B-21, Ile at B-27, Met at B-31), all the residues in human insulin that are involved in receptor binding, dimerization, and hexamerization have been conserved. A comparison of the structures of insulins from a range of species indicates that Polypterus insulin most closely resembles paddlefish insulin II (seven amino acid substitutions). In contrast, Polypterus glucagon (His-Ser- Gln-Gly-Thr-Phe-Thr-Asn-Asp-Tyr10-Thr-Lys-Tyr- Gln-Asp-Ser-Arg-Arg-Ala-Gln20-Asp-Phe-Val-Gln- Trp-Leu-Met-Ser-Asn) most closely resembles the glucagons from the gar Lepisosteus spatula and the bowfin Amia calva (four amino acid substitutions). The data are consistent with the conclusion based on comparison of morphological characteristics that the Polypterids are the most basal living group of the Actinopterygians with evolutionary connections to both the Acipenserids and the Neopterygians.
Collapse
Affiliation(s)
- J M Conlon
- Department of Biomedical Sciences, Creighton University Medical School, Omaha, Nebraska 68178, USA
| | | | | |
Collapse
|
16
|
Kristensen C, Kjeldsen T, Wiberg FC, Schäffer L, Hach M, Havelund S, Bass J, Steiner DF, Andersen AS. Alanine scanning mutagenesis of insulin. J Biol Chem 1997; 272:12978-83. [PMID: 9148904 DOI: 10.1074/jbc.272.20.12978] [Citation(s) in RCA: 171] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Alanine scanning mutagenesis has been used to identify specific side chains of insulin which strongly influence binding to the insulin receptor. A total of 21 new insulin analog constructs were made, and in addition 7 high pressure liquid chromatography-purified analogs were tested, covering alanine substitutions in positions B1, B2, B3, B4, B8, B9, B10, B11, B12, B13, B16, B17, B18, B20, B21, B22, B26, A4, A8, A9, A12, A13, A14, A15, A16, A17, A19, and A21. Binding data on the analogs revealed that the alanine mutations that were most disruptive for binding were at positions TyrA19, GlyB8, LeuB11, and GluB13, resulting in decreases in affinity of 1,000-, 33-, 14-, and 8-fold, respectively, relative to wild-type insulin. In contrast, alanine substitutions at positions GlyB20, ArgB22, and SerA9 resulted in an increase in affinity for the insulin receptor. The most striking finding is that B20Ala insulin retains high affinity binding to the receptor. GlyB20 is conserved in insulins from different species, and in the structure of the B-chain it appears to be essential for the shift from the alpha-helix B8-B19 to the beta-turn B20-B22. Thus, replacing GlyB20 with alanine most likely modifies the structure of the B-chain in this region, but this structural change appears to enhance binding to the insulin receptor.
Collapse
Affiliation(s)
- C Kristensen
- Department of Insulin Research, Novo Nordisk, 2880 Bagsvaerd, Denmark
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
The affinities of a number of insulin analogues for the human insulin receptor, a truncated soluble form of the insulin receptor, and the human insulin-like growth factor 1 receptor were determined. Insulin analogues with substitutions in the A13 or B17 positions were shown to have anomalous binding properties. This suggests that these positions, which are located in the hexamer-forming surface on the opposite side of the molecule from the classical binding site, constitute a second domain of the molecule important for receptor binding. In the present work, a model is proposed where each of the two alpha subunits of the insulin receptor contributes with a different binding region to the formation of the high-affinity binding site. Subsequently, a second molecule of insulin is able to bind to a low-affinity site involving only one of the alpha subunits, thus accounting for the curvilinear Scatchard plot. The affinity of the low-affinity site could be estimated using a high-affinity insulin analogue as the tracer. The model also provides the framework for a molecular explanation of the negative cooperativity phenomenon.
Collapse
Affiliation(s)
- L Schäffer
- Insulin Research, Novo Nordisk A/S, Bagsvaerd, Denmark
| |
Collapse
|
18
|
Drejer K. The bioactivity of insulin analogues from in vitro receptor binding to in vivo glucose uptake. DIABETES/METABOLISM REVIEWS 1992; 8:259-85. [PMID: 1338040 DOI: 10.1002/dmr.5610080305] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- K Drejer
- Diabetes Research, Novo Nordisk A/S, Bagsvaerd, Denmark
| |
Collapse
|
19
|
Importance of the character and configuration of residues B24, B25, and B26 in insulin-receptor interactions. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52312-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
20
|
Yu JH, Eng J, Yalow RS. Isolation and amino acid sequences of squirrel monkey (Saimiri sciurea) insulin and glucagon. Proc Natl Acad Sci U S A 1990; 87:9766-8. [PMID: 2263627 PMCID: PMC55254 DOI: 10.1073/pnas.87.24.9766] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
It was reported two decades ago that insulin was not detectable in the glucose-stimulated state in Saimiri sciurea, the New World squirrel monkey, by a radioimmunoassay system developed with guinea pig anti-pork insulin antibody and labeled pork insulin. With the same system, reasonable levels were observed in rhesus monkeys and chimpanzees. This suggested that New World monkeys, like the New World hystricomorph rodents such as the guinea pig and the coypu, might have insulins whose sequences differ markedly from those of Old World mammals. In this report we describe the purification and amino acid sequences of squirrel monkey insulin and glucagon. We demonstrate that the substitutions at B29, B27, A2, A4, and A17 of squirrel monkey insulin are identical with those previously found in another New World primate, the owl monkey (Aotus trivirgatus). The immunologic cross-reactivity of this insulin in our immunoassay system is only a few percent of that of human insulin. Squirrel monkey glucagon is identical with the usual glucagon found in Old World mammals, which predicts that the glucagons of other New World monkeys would not differ from the usual Old World mammalian glucagon. It appears that the peptides of the New World monkeys have diverged less from those of the Old World mammals than have those of the New World hystricomorph rodents. The striking improvements in peptide purification and sequencing have the potential for adding new information concerning the evolutionary divergence of species.
Collapse
Affiliation(s)
- J H Yu
- Solomon A. Berson Research Laboratory, Veterans Administration Medical Center, Bronx, NY 10468
| | | | | |
Collapse
|
21
|
Abstract
The amino acid sequence of the vasoactive intestinal polypeptide (VIP) is well conserved between species. Thus, all mammalian VIPs isolated so far, except that of the guinea pig, have the same amino acid sequence. This study describes the isolation and primary structure of sheep brain VIP. The purification was followed with a bioassay and a VIP receptor assay. The amino acid sequence of the isolated sheep VIP is identical to that of the pig, human, ox, rat, rabbit, goat and dog VIP.
Collapse
Affiliation(s)
- G Gafvelin
- Department of Biochemistry II, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
22
|
Sillard R, Agerberth B, Mutt V, Jörnvall H. Sheep neuropeptide Y. A third structural type of a highly conserved peptide. FEBS Lett 1989; 258:263-5. [PMID: 2599092 DOI: 10.1016/0014-5793(89)81669-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mammalian forms of neuropeptide Y (NPY) for which the amino acid sequences have previously been determined, are the human, pig, ox, rabbit, rat, and guinea-pig polypeptides. The only difference among these forms is at position 17, where pig and ox NPY have Leu and the others Met. We now show that sheep NPY differs from all the earlier characterized mammalian forms of NPY by having Asp instead of Glu at position 10. At position 17 it has Leu as do both pig and ox NPY. Consequently, 3 different structural types of mammalian NPY are now known.
Collapse
Affiliation(s)
- R Sillard
- Department of Biochemistry II, Karolinska Institutet, Stockholm, Sweden
| | | | | | | |
Collapse
|
23
|
Seino S, Steiner DF, Bell GI. Sequence of a New World primate insulin having low biological potency and immunoreactivity. Proc Natl Acad Sci U S A 1987; 84:7423-7. [PMID: 3118367 PMCID: PMC299308 DOI: 10.1073/pnas.84.21.7423] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The organization of the insulin gene of the owl or night monkey (Aotus trivirgatus), a New World primate, is similar to that of the human gene. The sequences of these two genes and flanking regions possess 84.3% homology. An unusual feature of the owl monkey gene is the partial duplication and insertion of a portion of the A-chain coding sequence into the 3' untranslated region. The insulin gene of this primate also lacks a region of tandem repeats that is present in the 5' flanking region of the human and chimpanzee genes. Owl monkey preproinsulin has 85.5% identity with the human insulin precursor and is the most divergent of the primate insulins/preproinsulins yet described. The differences between owl monkey and human preproinsulin include three substitutions in the signal peptide, two in the B chain, seven in the C peptide, and three in the A chain. One of these replacements is the conservative substitution of valine for isoleucine at position A2, an invariant site in all other vertebrate insulins and insulin-like growth factors. The substitutions in owl monkey insulin at B9, B27, A2, A4, and A17 alter its structure so that it has only 20% of the receptor-binding activity and 1% of the affinity with guinea pig anti-porcine insulin antibodies as compared to human insulin.
Collapse
Affiliation(s)
- S Seino
- Howard Hughes Medical Institute, University of Chicago, IL 60637
| | | | | |
Collapse
|