insulin-like growth factor receptor Dotaz Zobrazit nápovědu
Insulin and insulin-like growth factor 1 (IGF-1) are closely related hormones involved in the regulation of metabolism and growth. They elicit their functions through activation of tyrosine kinase-type receptors: insulin receptors (IR-A and IR-B) and IGF-1 receptor (IGF-1R). Despite similarity in primary and three-dimensional structures, insulin and IGF-1 bind the noncognate receptor with substantially reduced affinity. We prepared [d-HisB24, GlyB31, TyrB32]-insulin, which binds all three receptors with high affinity (251 or 338% binding affinity to IR-A respectively to IR-B relative to insulin and 12.4% binding affinity to IGF-1R relative to IGF-1). We prepared other modified insulins with the aim of explaining the versatility of [d-HisB24, GlyB31, TyrB32]-insulin. Through structural, activity, and kinetic studies of these insulin analogs, we concluded that the ability of [d-HisB24, GlyB31, TyrB32]-insulin to stimulate all three receptors is provided by structural changes caused by a reversed chirality at the B24 combined with the extension of the C terminus of the B chain by two extra residues. We assume that the structural changes allow the directing of the B chain C terminus to some extra interactions with the receptors. These unusual interactions lead to a decrease of dissociation rate from the IR and conversely enable easier association with IGF-1R. All of the structural changes were made at the hormones' Site 1, which is thought to interact with the Site 1 of the receptors. The results of the study suggest that merely modifications of Site 1 of the hormone are sufficient to change the receptor specificity of insulin.
- Klíčová slova
- Site 1, binding, insulin, insulin receptor, insulin-like growth factor (IGF), kinetics, protein design, structure-function,
- MeSH
- insulinu podobný růstový faktor I chemie genetika metabolismus MeSH
- inzulin agonisté metabolismus MeSH
- kinetika MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu chemie genetika metabolismus MeSH
- receptory somatomedinů chemie genetika metabolismus MeSH
- sekvence aminokyselin MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- IGF1R protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- inzulin MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
- receptory somatomedinů MeSH
Insulin and insulin-like growth factors I and II are closely related protein hormones. Their distinct evolution has resulted in different yet overlapping biological functions with insulin becoming a key regulator of metabolism, whereas insulin-like growth factors (IGF)-I/II are major growth factors. Insulin and IGFs cross-bind with different affinities to closely related insulin receptor isoforms A and B (IR-A and IR-B) and insulin-like growth factor type I receptor (IGF-1R). Identification of structural determinants in IGFs and insulin that trigger their specific signaling pathways is of increasing importance in designing receptor-specific analogs with potential therapeutic applications. Here, we developed a straightforward protocol for production of recombinant IGF-II and prepared six IGF-II analogs with IGF-I-like mutations. All modified molecules exhibit significantly reduced affinity toward IR-A, particularly the analogs with a Pro-Gln insertion in the C-domain. Moreover, one of the analogs has enhanced binding affinity for IGF-1R due to a synergistic effect of the Pro-Gln insertion and S29N point mutation. Consequently, this analog has almost a 10-fold higher IGF-1R/IR-A binding specificity in comparison with native IGF-II. The established IGF-II purification protocol allowed for cost-effective isotope labeling required for a detailed NMR structural characterization of IGF-II analogs that revealed a link between the altered binding behavior of selected analogs and conformational rearrangement of their C-domains.
- Klíčová slova
- insulin, insulin receptor, insulin-like growth factor (IGF), nuclear magnetic resonance (NMR), structural biology, structure-function,
- MeSH
- CD antigeny chemie genetika metabolismus MeSH
- insulinu podobný růstový faktor II chemie genetika metabolismus MeSH
- lidé MeSH
- missense mutace MeSH
- protein - isoformy chemie genetika metabolismus MeSH
- proteinové domény MeSH
- receptor IGF typ 1 chemie genetika metabolismus MeSH
- receptor inzulinu chemie genetika metabolismus MeSH
- rekombinantní proteiny chemie genetika metabolismus MeSH
- substituce aminokyselin MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- CD antigeny MeSH
- IGF2 protein, human MeSH Prohlížeč
- INSR protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor II MeSH
- protein - isoformy MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
- rekombinantní proteiny MeSH
Insulin-like growth factors 2 and 1 (IGF2 and IGF1) and insulin are closely related hormones that are responsible for the regulation of metabolic homeostasis, development and growth of the organism. Physiological functions of insulin and IGF1 are relatively well-studied, but information about the role of IGF2 in the body is still sparse. Recent discoveries called attention to emerging functions of IGF2 in the brain, where it could be involved in processes of learning and memory consolidation. It was also proposed that these functions could be mediated by the receptor for IGF2 (IGF2R). Nevertheless, little is known about the mechanism of signal transduction through this receptor. Here we produced His-tagged domain 11 (D11), an IGF2-binding element of IGF2R; we immobilized it on the solid support through a well-defined sandwich, consisting of neutravidin, biotin and synthetic anti-His-tag antibodies. Next, we prepared specifically radiolabeled [125I]-monoiodotyrosyl-Tyr2-IGF2 and optimized a sensitive and robust competitive radioligand binding assay for determination of the nanomolar binding affinities of hormones for D11 of IGF2. The assay will be helpful for the characterization of new IGF2 mutants to study the functions of IGF2R and the development of new compounds for the treatment of neurological disorders.
- MeSH
- insulinu podobný růstový faktor I metabolismus MeSH
- insulinu podobný růstový faktor II metabolismus MeSH
- kompetitivní vazba MeSH
- kultivované buňky MeSH
- lidé MeSH
- radioizotopy jodu MeSH
- radioligandová zkouška metody MeSH
- receptor IGF typ 2 imunologie ultrastruktura MeSH
- signální transdukce MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- IGF1 protein, human MeSH Prohlížeč
- IGF2 protein, human MeSH Prohlížeč
- IGF2R protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- insulinu podobný růstový faktor II MeSH
- Iodine-125 MeSH Prohlížeč
- radioizotopy jodu MeSH
- receptor IGF typ 2 MeSH
Information on how insulin and insulin-like growth factors 1 and 2 (IGF-1 and -2) activate insulin receptors (IR-A and -B) and the IGF-1 receptor (IGF-1R) is crucial for understanding the difference in the biological activities of these peptide hormones. Cryo-EM studies have revealed that insulin uses its binding sites 1 and 2 to interact with IR-A and have identified several critical residues in binding site 2. However, mutagenesis studies suggest that Ile-A10, Ser-A12, Leu-A13, and Glu-A17 also belong to insulin's site 2. Here, to resolve this discrepancy, we mutated these insulin residues and the equivalent residues in IGFs. Our findings revealed that equivalent mutations in the hormones can result in differential biological effects and that these effects can be receptor-specific. We noted that the insulin positions A10 and A17 are important for its binding to IR-A and IR-B and IGF-1R and that A13 is important only for IR-A and IR-B binding. The IGF-1/IGF-2 positions 51/50 and 54/53 did not appear to play critical roles in receptor binding, but mutations at IGF-1 position 58 and IGF-2 position 57 affected the binding. We propose that IGF-1 Glu-58 interacts with IGF-1R Arg-704 and belongs to IGF-1 site 1, a finding supported by the NMR structure of the less active Asp-58-IGF-1 variant. Computational analyses indicated that the aforementioned mutations can affect internal insulin dynamics and inhibit adoption of a receptor-bound conformation, important for binding to receptor site 1. We provide a molecular model and alternative hypotheses for how the mutated insulin residues affect activity.
- Klíčová slova
- NMR structure, complex, hormone analog, insulin, insulin-like growth factor (IGF), molecular dynamics, mutagenesis, peptide hormone, receptor autophosphorylation, receptor binding, receptor tyrosine kinase, structural biology, structure-function,
- MeSH
- insulinu podobný růstový faktor I chemie genetika MeSH
- insulinu podobný růstový faktor II chemie genetika MeSH
- inzulin analogy a deriváty chemická syntéza chemie genetika MeSH
- lidé MeSH
- mnohočetné abnormality genetika MeSH
- mutace genetika MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- poruchy růstu genetika MeSH
- proteinové domény genetika MeSH
- receptor IGF typ 1 chemie genetika MeSH
- receptor inzulinu chemie genetika MeSH
- sekvence aminokyselin genetika MeSH
- vazba proteinů genetika MeSH
- vazebná místa genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- IGF1R protein, human MeSH Prohlížeč
- IGF2 protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- insulinu podobný růstový faktor II MeSH
- inzulin MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
Insulin-like growth factors 1 and 2 (IGF-1 and -2, respectively) are protein hormones involved not only in normal growth and development but also in life span regulation and cancer. They exert their functions mainly through the IGF-1R or by binding to isoform A of the insulin receptor (IR-A). The development of IGF-1 and IGF-2 antagonists is of great clinical interest. Mutations of A4 and A8 sites of human insulin lead to disproportionate effects on hormone IR binding and activation. Here, we systematically modified IGF-1 sites 45, 46, and 49 and IGF-2 sites 45 and 48, which correspond, or are close, to insulin sites A4 and A8. The IGF-1R and IR-A binding and autophosphorylation potencies of these analogues were characterized. They retained the main IGF-1R-related properties, but the hormones with His49 in IGF-1 and His48 in IGF-2 showed significantly higher affinities for IR-A and for IR-B, being the strongest IGF-1- and IGF-2-like binders of these receptors ever reported. All analogues activated IR-A and IGF-1R without major discrepancies in their binding affinities. This study revealed that IR-A and IGF-1R contain specific sites, likely parts of their so-called sites 2', which can interact differently with specifically modified IGF analogues. Moreover, a clear importance of IGF-2 site 44 for effective hormone folding was also observed. These findings may facilitate novel and rational engineering of new hormone analogues for IR-A and IGF-1R studies and for potential medical applications.
- MeSH
- fosforylace MeSH
- insulinu podobný růstový faktor I chemie genetika MeSH
- insulinu podobný růstový faktor II chemie genetika MeSH
- inzulin chemie metabolismus MeSH
- lidé MeSH
- ligandy MeSH
- molekulární evoluce MeSH
- mutace MeSH
- protein - isoformy MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu chemie metabolismus MeSH
- receptory somatomedinů chemie genetika MeSH
- signální transdukce MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- IGF1R protein, human MeSH Prohlížeč
- IGF2 protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- insulinu podobný růstový faktor II MeSH
- inzulin MeSH
- ligandy MeSH
- protein - isoformy MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
- receptory somatomedinů MeSH
Insulin, insulin-like growth factors 1 and 2 (IGF-1 and -2, respectively), and their receptors (IR and IGF-1R) are the key elements of a complex hormonal system that is essential for the development and functioning of humans. The C and D domains of IGFs (absent in insulin) likely play important roles in the differential binding of IGF-1 and -2 to IGF-1R and to the isoforms of IR (IR-A and IR-B) and specific activation of these receptors. Here, we attempted to probe the impact of IGF-1 and IGF-2 D domains (DI and DII, respectively) and the IGF-2 C domain (CII) on the receptor specificity of these hormones. For this, we made two types of insulin hybrid analogues: (i) with the C-terminus of the insulin A chain extended by the amino acids from the DI and DII domains and (ii) with the C-terminus of the insulin B chain extended by some amino acids derived from the CII domain. The receptor binding affinities of these analogues and their receptor autophosphorylation potentials were characterized. Our results indicate that the DI domain has a more negative impact than the DII domain does on binding to IR, and that the DI domain Pro-Leu-Lys residues are important factors for a different IR-A versus IR-B binding affinity of IGF-1. We also showed that the additions of amino acids that partially "mimic" the CII domain, to the C-terminus of the insulin B chain, change the binding and autophosphorylation specificity of insulin in favor of the "metabolic" IR-B isoform. This opens new venues for rational enhancement of insulin IR-B specificity by modifications beyond the C-terminus of its B chain.
- MeSH
- embryo savčí cytologie metabolismus MeSH
- fibroblasty cytologie metabolismus MeSH
- fosforylace MeSH
- hypoglykemika metabolismus MeSH
- insulinu podobný růstový faktor I metabolismus MeSH
- insulinu podobný růstový faktor II metabolismus MeSH
- inzulin metabolismus MeSH
- konformace proteinů MeSH
- kultivované buňky MeSH
- lidé MeSH
- lymfocyty cytologie metabolismus MeSH
- molekulární sondy metabolismus MeSH
- myši knockoutované MeSH
- myši MeSH
- receptor IGF typ 1 metabolismus MeSH
- receptor inzulinu metabolismus MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie aminokyselin MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- hypoglykemika MeSH
- insulinu podobný růstový faktor I MeSH
- insulinu podobný růstový faktor II MeSH
- inzulin MeSH
- molekulární sondy MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
The plasminogen system is harnessed in a wide variety of physiological processes, such as fibrinolysis, cell migration, or efferocytosis; and accordingly, it is essential upon inflammation, tissue remodeling, wound healing, and for homeostatic maintenance in general. Previously, we identified a plasminogen receptor in the mannose 6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R, CD222). Here, we demonstrate by means of genetic knockdown, knockout, and rescue approaches combined with functional studies that M6P/IGF2R is up-regulated on the surface of macrophages, recognizes plasminogen exposed on the surface of apoptotic cells, and mediates plasminogen-induced efferocytosis. The level of uptake of plasminogen-coated apoptotic cells inversely correlates with the TNF-α production by phagocytes indicating tissue clearance without inflammation by this mechanism. Our results reveal an up-to-now undetermined function of M6P/IGF2R in clearance of apoptotic cells, which is crucial for tissue homeostasis.
- Klíčová slova
- M6P/IGF2R, efferocytosis, macrophages, plasminogen, tissue homeostasis,
- MeSH
- buněčná diferenciace účinky léků MeSH
- fagocytóza účinky léků MeSH
- fibroblasty účinky léků metabolismus MeSH
- genový knockout MeSH
- Jurkat buňky MeSH
- lidé MeSH
- makrofágy cytologie účinky léků metabolismus MeSH
- myši MeSH
- plazminogen farmakologie MeSH
- receptor IGF typ 2 metabolismus MeSH
- THP-1 buňky MeSH
- TNF-alfa metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- plazminogen MeSH
- receptor IGF typ 2 MeSH
- TNF-alfa MeSH
Interest in growth hormone (GH) is inextricably linked to the need for in depth understanding of the somatomedins (insulin-like growth factors) which are polypeptides structurally similar to insulin and with broad physiological activity. To date, the most commonly known is Insulin-Like Growth Factor I (IGF-I). Despite considerable current knowledge of IGF-I, however, its bioactivity is incompletely understood. Measurement of IGF-I is of the utmost importance in the diagnosis and treatment of, for example acromegaly and growth hormone deficiency. The development of recombinant IGF-I, has allowed its use in such cases. Clinical practice, however, shows that few young/adult patients will benefit from treatment with the rIGF-I, mecasermin, given the number of adverse effects found. This review focuses on current knowledge mainly related to IGF-I and the use of its recombinant form (rIGF-I) in clinical practice. Several functions of IGI-II have been elucidated but their clinical significance is unclear.
- Klíčová slova
- Acid Labile Subunit, Human Growth Hormone, IGF Binding Proteins, IGF-I receptor, II, Insulin Receptor Isoform A, Insulin-Like Growth Factor I, Mecasermin, Recombinant Human Growth Hormone, Somatomedins, acromegaly, growth hormone deficiency,
- MeSH
- akromegalie farmakoterapie metabolismus MeSH
- insulinu podobný růstový faktor I metabolismus terapeutické užití MeSH
- lidé MeSH
- rekombinantní proteiny MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- insulinu podobný růstový faktor I MeSH
- rekombinantní proteiny MeSH
Cardiac hypertrophy is the result of responses to various physiological or pathological stimuli. Recently, we showed that polycystin-1 participates in cardiomyocyte hypertrophy elicited by pressure overload and mechanical stress. Interestingly, polycystin-1 knockdown does not affect phenylephrine-induced cardiomyocyte hypertrophy, suggesting that the effects of polycystin-1 are stimulus-dependent. In this study, we aimed to identify the role of polycystin-1 in insulin-like growth factor-1 (IGF-1) signaling in cardiomyocytes. Polycystin-1 knockdown completely blunted IGF-1-induced cardiomyocyte hypertrophy. We then investigated the molecular mechanism underlying this result. We found that polycystin-1 silencing impaired the activation of the IGF-1 receptor, Akt, and ERK1/2 elicited by IGF-1. Remarkably, IGF-1-induced IGF-1 receptor, Akt, and ERK1/2 phosphorylations were restored when protein tyrosine phosphatase 1B was inhibited, suggesting that polycystin-1 knockdown deregulates this phosphatase in cardiomyocytes. Moreover, protein tyrosine phosphatase 1B inhibition also restored IGF-1-dependent cardiomyocyte hypertrophy in polycystin-1-deficient cells. Our findings provide the first evidence that polycystin-1 regulates IGF-1-induced cardiomyocyte hypertrophy through a mechanism involving protein tyrosine phosphatase 1B.
- MeSH
- fosforylace MeSH
- genový knockdown MeSH
- insulinu podobný růstový faktor I * metabolismus MeSH
- kardiomegalie * metabolismus patologie genetika MeSH
- kardiomyocyty * metabolismus patologie MeSH
- kationtové kanály TRPP * metabolismus genetika MeSH
- krysa rodu Rattus MeSH
- kultivované buňky MeSH
- protoonkogenní proteiny c-akt metabolismus MeSH
- receptor IGF typ 1 * metabolismus genetika MeSH
- signální transdukce MeSH
- tyrosinfosfatasa nereceptorového typu 1 metabolismus genetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- insulinu podobný růstový faktor I * MeSH
- kationtové kanály TRPP * MeSH
- polycystic kidney disease 1 protein MeSH Prohlížeč
- protoonkogenní proteiny c-akt MeSH
- receptor IGF typ 1 * MeSH
- tyrosinfosfatasa nereceptorového typu 1 MeSH
OBJECTIVE: The insulin/IGF superfamily is conserved across vertebrates and invertebrates. Our team has identified five viruses containing genes encoding viral insulin/IGF-1 like peptides (VILPs) closely resembling human insulin and IGF-1. This study aims to characterize the impact of Mandarin fish ranavirus (MFRV) and Lymphocystis disease virus-Sa (LCDV-Sa) VILPs on the insulin/IGF system for the first time. METHODS: We chemically synthesized single chain (sc, IGF-1 like) and double chain (dc, insulin like) forms of MFRV and LCDV-Sa VILPs. Using cell lines overexpressing either human insulin receptor isoform A (IR-A), isoform B (IR-B) or IGF-1 receptor (IGF1R), and AML12 murine hepatocytes, we characterized receptor binding, insulin/IGF signaling. We further characterized the VILPs' effects of proliferation and IGF1R and IR gene expression, and compared them to native ligands. Additionally, we performed insulin tolerance test in CB57BL/6 J mice to examine in vivo effects of VILPs on blood glucose levels. Finally, we employed cryo-electron microscopy (cryoEM) to analyze the structure of scMFRV-VILP in complex with the IGF1R ectodomain. RESULTS: VILPs can bind to human IR and IGF1R, stimulate receptor autophosphorylation and downstream signaling pathways. Notably, scMFRV-VILP exhibited a particularly strong affinity for IGF1R, with a mere 10-fold decrease compared to human IGF-1. At high concentrations, scMFRV-VILP selectively reduced IGF-1 stimulated IGF1R autophosphorylation and Erk phosphorylation (Ras/MAPK pathway), while leaving Akt phosphorylation (PI3K/Akt pathway) unaffected, indicating a potential biased inhibitory function. Prolonged exposure to MFRV-VILP led to a significant decrease in IGF1R gene expression in IGF1R overexpressing cells and AML12 hepatocytes. Furthermore, insulin tolerance test revealed scMFRV-VILP's sustained glucose-lowering effect compared to insulin and IGF-1. Finally, cryo-EM analysis revealed that scMFRV-VILP engages with IGF1R in a manner closely resembling IGF-1 binding, resulting in a highly analogous structure. CONCLUSIONS: This study introduces MFRV and LCDV-Sa VILPs as novel members of the insulin/IGF superfamily. Particularly, scMFRV-VILP exhibits a biased inhibitory effect on IGF1R signaling at high concentrations, selectively inhibiting IGF-1 stimulated IGF1R autophosphorylation and Erk phosphorylation, without affecting Akt phosphorylation. In addition, MFRV-VILP specifically regulates IGF-1R gene expression and IGF1R protein levels without affecting IR. CryoEM analysis confirms that scMFRV-VILP' binding to IGF1R is mirroring the interaction pattern observed with IGF-1. These findings offer valuable insights into IGF1R action and inhibition, suggesting potential applications in development of IGF1R specific inhibitors and advancing long-lasting insulins.
- Klíčová slova
- Biased signaling, IGF-1, IGF1 receptor, IGF1 receptor inhibition, Insulin, Iridoviridae, Viral insulin/IGF-1 like peptides (VILPs),
- MeSH
- elektronová kryomikroskopie MeSH
- exprese genu MeSH
- fosfatidylinositol-3-kinasy metabolismus MeSH
- fosforylace MeSH
- insulinu podobný růstový faktor I * genetika metabolismus MeSH
- inzulin metabolismus MeSH
- lidé MeSH
- myši MeSH
- protein - isoformy metabolismus MeSH
- protoonkogenní proteiny c-akt metabolismus MeSH
- receptor IGF typ 1 * genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fosfatidylinositol-3-kinasy MeSH
- IGF1R protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I * MeSH
- inzulin MeSH
- protein - isoformy MeSH
- protoonkogenní proteiny c-akt MeSH
- receptor IGF typ 1 * MeSH