Protease-resistant form of insulin-like growth factor-binding protein 5 is an inhibitor of insulin-like growth factor-I actions on porcine smooth muscle cells in culture.
| References: | Endocrinology. 1995 Oct;136(10):4168-73. (PMID: 7545099) J Clin Invest. 1997 Jan 15;99(2):200-8. (PMID: 9005988) J Biol Chem. 1996 Mar 15;271(11):6099-106. (PMID: 8626396) J Biol Chem. 1996 Feb 23;271(8):4280-8. (PMID: 8626775) Endocrinology. 1996 Nov;137(11):4571-5. (PMID: 8895319) J Cell Biol. 1971 Jul;50(1):172-86. (PMID: 4327464) J Cell Physiol. 1983 May;115(2):137-42. (PMID: 6601662) Methods Enzymol. 1983;91:399-413. (PMID: 6855591) J Clin Invest. 1985 Mar;75(3):1028-36. (PMID: 2984251) Endocrinology. 1985 Jul;117(1):77-83. (PMID: 4040014) J Clin Invest. 1985 Jun;75(6):1914-8. (PMID: 4008644) J Biol Chem. 1988 Oct 5;263(28):14203-10. (PMID: 2971653) Biochem Biophys Res Commun. 1988 Oct 14;156(1):199-204. (PMID: 2972283) Biochem J. 1989 Feb 15;258(1):267-72. (PMID: 2539101) Proc Natl Acad Sci U S A. 1989 Nov;86(21):8338-42. (PMID: 2479022) Circ Res. 1990 Jul;67(1):61-7. (PMID: 2114227) Biochem Biophys Res Commun. 1991 Apr 30;176(2):756-63. (PMID: 1709017) Cancer Res. 1991 Jun 1;51(11):2813-9. (PMID: 1709585) Biochem Biophys Res Commun. 1991 Aug 30;179(1):579-85. (PMID: 1715698) Hypertension. 1991 Dec;18(6):742-7. (PMID: 1743755) Diabetologia. 1992 Feb;35(2):104-8. (PMID: 1312491) J Biol Chem. 1992 Jun 15;267(17):11949-56. (PMID: 1376315) J Cell Biochem. 1992 Feb;48(2):215-26. (PMID: 1377702) J Biol Chem. 1992 Nov 5;267(31):22467-72. (PMID: 1385400) J Clin Invest. 1992 Nov;90(5):1926-31. (PMID: 1430215) Growth Regul. 1993 Mar;3(1):82-4. (PMID: 7683542) J Cell Biol. 1993 May;121(3):679-87. (PMID: 7683690) J Clin Endocrinol Metab. 1993 May;76(5):1153-9. (PMID: 7684391) J Cell Physiol. 1993 Oct;157(1):52-60. (PMID: 7691836) J Clin Invest. 1994 Mar;93(3):1266-74. (PMID: 8132765) Endocrinology. 1994 Oct;135(4):1385-91. (PMID: 7523096) Endocrinology. 1994 Dec;135(6):2358-63. (PMID: 7527332) Endocrinology. 1995 Jun;136(6):2470-6. (PMID: 7538463) J Clin Invest. 1996 Jan 1;97(1):139-45. (PMID: 8550825) |
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| Grant Information: | HL-56850 United States HL NHLBI NIH HHS |
| Substance Nomenclature: | 0 (Culture Media, Conditioned) 0 (Insulin-Like Growth Factor Binding Protein 1) 0 (Insulin-Like Growth Factor Binding Protein 5) 0 (Peptide Fragments) 0 (Recombinant Proteins) 67763-96-6 (Insulin-Like Growth Factor I) 7006-34-0 (Asparagine) 94ZLA3W45F (Arginine) EC 3.4.24.- (Metalloendopeptidases) VC2W18DGKR (Thymidine) |
| Entry Date(s): | Date Created: 19971120 Date Completed: 19980109 Latest Revision: 20181113 |
| Update Code: | 20240829 |
| PubMed Central ID: | PMC508461 |
| DOI: | 10.1172/JCI119803 |
| PMID: | 9366575 |
| Autor: | Imai Y; Department of Medicine, University of North Carolina School of Medicine, Chapel Hill 27599-7170, USA., Busby WH Jr, Smith CE, Clarke JB, Garmong AJ, Horwitz GD, Rees C, Clemmons DR |
| Jazyk: | angličtina |
| Zdroj: | The Journal of clinical investigation [J Clin Invest] 1997 Nov 15; Vol. 100 (10), pp. 2596-605. |
| DOI: | 10.1172/JCI119803 |
| Abstrakt: | IGFs are pleiotrophic mitogens for porcine smooth muscle cells (pSMC) in culture. The effects of IGFs on cells are modulated by various insulin-like growth factor-binding proteins (IGFBP). IGFBP-5 is synthesized by pSMC and binds to the extracellular matrix. However, IGFBP-5 is also secreted into conditioned medium of cultured cells and is cleaved into fragments by a concomitantly produced protease. These fragments have reduced affinity for the IGFs and cleavage makes it difficult to assess the role of intact IGFBP-5. To study the consequence of accumulation of intact IGFBP-5 in medium, we determined the cleavage site in IGFBP-5 and prepared a protease resistant mutant. Amino acid sequencing of purified IGFBP-5 fragments suggested Arg138-Arg139 as the primary cleavage site. Arg138-Arg139-->Asn138-Asn139 mutations were introduced to create protease-resistant IGFBP-5, which has the same affinity for IGF-I as the native protein. This mutant IGFBP-5 remained intact even after 24 h of incubation and it inhibited several IGF-I actions when added to pSMC culture medium. The mutant IGFBP-5 (500 ng/ml) decreased IGF-I stimulated cellular DNA synthesis by 84%, protein synthesis by 77%, and it inhibited IGF-I stimulated migration of pSMC by 77%. It also inhibited IGF-I stimulation of IRS-1 phosphorylation. In contrast, the same amount of native IGFBP-5 did not inhibit IGF-I actions. The significance of inhibitory effects of the protease resistant IGFBP-5 was further demonstrated in pSMC transfected with mutant or native IGFBP-5 cDNAs. The mutant IGFBP-5 accumulated in culture medium of transfected cells, while native IGFBP-5 was degraded into fragments, PSMC overexpressing the mutant IGFBP-5 also responded poorly to IGF-I compared with mock transfected cells. IGF-I (5 ng/ml) increased [35S]methionine incorporation into control cells by 36% above the basal level, but it did not significantly change (4%) in pSMC cultures that were producing the mutant IGFBP-5. In conclusion, the accumulation of protease-resistant IGFBP-5 in the medium was inhibitory to IGF-I actions on pSMC. This suggests that proteolysis can prevent IGFBP-5 from acting as an inhibitor of IGF-I-stimulated effects and that it serves as an important mechanism for regulating cellular responsiveness to IGF-I. |
| Databáze: | MEDLINE |
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