Abstract
Insulin-like growth factor binding protein-4 (IGFBP-4) is a 24-26-kD protein expressed by a variety of cell types in vivo and in vitro. Treatment of normal adult human fibroblasts with 10 nM insulin-like growth factor II (IGF-II) for 24 h resulted in an 85% decrease in endogenous IGFBP-4, as assessed by Western ligand blot analysis of the conditioned medium. Incubation of human fibroblast-conditioned medium (HFCM) with IGF-II under cell-free conditions led to a similar loss of IGFBP-4. This posttranslationally regulated decrease in IGFBP-4 appeared to be due to a protease in HFCM: (a) It could be prevented with specific protease inhibitors or incubation at 4 degrees C; (b) proteolysis of recombinant human (rh) IGFBP-4 required HFCM; (c) immunoblotting and radiolabeling confirmed cleavage of IGFBP-4 into 18- and 14-kD IGFBP-4 fragments. The protease was specific for IGFBP-4, and was strictly dependent on IGFs for activation. IGF-II was the most effective of the natural and mutant IGFs tested, inducing complete hydrolysis of rhIGFBP-4 at a molar ratio of 0.25:1 (IGF/IGFBP-4). Simian virus 40-transformed adult human fibroblasts also expressed IGFBP-4 and IGFBP-4 protease, as well as an inhibitor of IGFBP-4 proteolysis. In biological studies, intact rhIGFBP-4 potently inhibited IGF-I-stimulated [3H]aminoisobutyric acid uptake, whereas proteolyzed rhIGFBP-4 had no inhibitory effect. In conclusion, these data provide evidence for a novel IGF-dependent IGFBP-4-specific protease that modifies IGFBP-4 structure and function, and indicate a preferential role for IGF-II in its activation. Posttranslational regulation of IGFBP-4 may provide a means for cooperative control of local cell growth by IGF-I and IGF-II.
Full text
PDF








Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bachrach L. K., Liu F. R., Burrow G. N., Eggo M. C. Characterization of insulin-like growth factor-binding proteins from sheep thyroid cells. Endocrinology. 1989 Dec;125(6):2831–2838. doi: 10.1210/endo-125-6-2831. [DOI] [PubMed] [Google Scholar]
- Bale L. K., Conover C. A. Regulation of insulin-like growth factor binding protein-3 messenger ribonucleic acid expression by insulin-like growth factor I. Endocrinology. 1992 Aug;131(2):608–614. doi: 10.1210/endo.131.2.1379162. [DOI] [PubMed] [Google Scholar]
- Bautista C. M., Mohan S., Baylink D. J. Insulin-like growth factors I and II are present in the skeletal tissues of ten vertebrates. Metabolism. 1990 Jan;39(1):96–100. doi: 10.1016/0026-0495(90)90154-5. [DOI] [PubMed] [Google Scholar]
- Baxter R. C., Martin J. L. Binding proteins for the insulin-like growth factors: structure, regulation and function. Prog Growth Factor Res. 1989;1(1):49–68. doi: 10.1016/0955-2235(89)90041-0. [DOI] [PubMed] [Google Scholar]
- Binkert C., Landwehr J., Mary J. L., Schwander J., Heinrich G. Cloning, sequence analysis and expression of a cDNA encoding a novel insulin-like growth factor binding protein (IGFBP-2). EMBO J. 1989 Sep;8(9):2497–2502. doi: 10.1002/j.1460-2075.1989.tb08386.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown A. L., Chiariotti L., Orlowski C. C., Mehlman T., Burgess W. H., Ackerman E. J., Bruni C. B., Rechler M. M. Nucleotide sequence and expression of a cDNA clone encoding a fetal rat binding protein for insulin-like growth factors. J Biol Chem. 1989 Mar 25;264(9):5148–5154. [PubMed] [Google Scholar]
- Böni-Schnetzler M., Schmid C., Mary J. L., Zimmerli B., Meier P. J., Zapf J., Schwander J., Froesch E. R. Insulin regulates the expression of the insulin-like growth factor binding protein 2 mRNA in rat hepatocytes. Mol Endocrinol. 1990 Sep;4(9):1320–1326. doi: 10.1210/mend-4-9-1320. [DOI] [PubMed] [Google Scholar]
- Camacho-Hubner C., McCusker R. H., Clemmons D. R. Secretion and biological actions of insulin-like growth factor binding proteins in two human tumor-derived cell lines in vitro. J Cell Physiol. 1991 Aug;148(2):281–289. doi: 10.1002/jcp.1041480214. [DOI] [PubMed] [Google Scholar]
- Campbell P. G., Novak J. F., Yanosick T. B., McMaster J. H. Involvement of the plasmin system in dissociation of the insulin-like growth factor-binding protein complex. Endocrinology. 1992 Mar;130(3):1401–1412. doi: 10.1210/endo.130.3.1371448. [DOI] [PubMed] [Google Scholar]
- Ceda G. P., Fielder P. J., Henzel W. J., Louie A., Donovan S. M., Hoffman A. R., Rosenfeld R. G. Differential effects of insulin-like growth factor (IGF)-I and IGF-II on the expression of IGF binding proteins (IGFBPs) in a rat neuroblastoma cell line: isolation and characterization of two forms of IGFBP-4. Endocrinology. 1991 Jun;128(6):2815–2824. doi: 10.1210/endo-128-6-2815. [DOI] [PubMed] [Google Scholar]
- Cheung P. T., Smith E. P., Shimasaki S., Ling N., Chernausek S. D. Characterization of an insulin-like growth factor binding protein (IGFBP-4) produced by the B104 rat neuronal cell line: chemical and biological properties and differential synthesis by sublines. Endocrinology. 1991 Aug;129(2):1006–1015. doi: 10.1210/endo-129-2-1006. [DOI] [PubMed] [Google Scholar]
- Clemmons D. R., Cascieri M. A., Camacho-Hubner C., McCusker R. H., Bayne M. L. Discrete alterations of the insulin-like growth factor I molecule which alter its affinity for insulin-like growth factor-binding proteins result in changes in bioactivity. J Biol Chem. 1990 Jul 25;265(21):12210–12216. [PubMed] [Google Scholar]
- Clemmons D. R., Thrailkill K. M., Handwerger S., Busby W. H., Jr Three distinct forms of insulin-like growth factor binding proteins are released by decidual cells in culture. Endocrinology. 1990 Aug;127(2):643–650. doi: 10.1210/endo-127-2-643. [DOI] [PubMed] [Google Scholar]
- Conover C. A. A unique receptor-independent mechanism by which insulinlike growth factor I regulates the availability of insulinlike growth factor binding proteins in normal and transformed human fibroblasts. J Clin Invest. 1991 Oct;88(4):1354–1361. doi: 10.1172/JCI115441. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conover C. A., Baker B. K., Hintz R. L. Cultured human fibroblasts secrete insulin-like growth factor IA prohormone. J Clin Endocrinol Metab. 1989 Jul;69(1):25–30. doi: 10.1210/jcem-69-1-25. [DOI] [PubMed] [Google Scholar]
- Conover C. A., Liu F., Powell D., Rosenfeld R. G., Hintz R. L. Insulin-like growth factor binding proteins from cultured human fibroblasts. Characterization and hormonal regulation. J Clin Invest. 1989 Mar;83(3):852–859. doi: 10.1172/JCI113968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conover C. A. Potentiation of insulin-like growth factor (IGF) action by IGF-binding protein-3: studies of underlying mechanism. Endocrinology. 1992 Jun;130(6):3191–3199. doi: 10.1210/endo.130.6.1375895. [DOI] [PubMed] [Google Scholar]
- Conover C. A. Regulation of insulin-like growth factor (IGF)-binding protein synthesis by insulin and IGF-I in cultured bovine fibroblasts. Endocrinology. 1990 Jun;126(6):3139–3145. doi: 10.1210/endo-126-6-3139. [DOI] [PubMed] [Google Scholar]
- Conover C. A., Ronk M., Lombana F., Powell D. R. Structural and biological characterization of bovine insulin-like growth factor binding protein-3. Endocrinology. 1990 Dec;127(6):2795–2803. doi: 10.1210/endo-127-6-2795. [DOI] [PubMed] [Google Scholar]
- Culouscou J. M., Shoyab M. Purification of a colon cancer cell growth inhibitor and its identification as an insulin-like growth factor binding protein. Cancer Res. 1991 Jun 1;51(11):2813–2819. [PubMed] [Google Scholar]
- Erickson G. F., Nakatani A., Ling N., Shimasaki S. Cyclic changes in insulin-like growth factor-binding protein-4 messenger ribonucleic acid in the rat ovary. Endocrinology. 1992 Feb;130(2):625–636. doi: 10.1210/endo.130.2.1370792. [DOI] [PubMed] [Google Scholar]
- Froesch E. R., Schmid C., Schwander J., Zapf J. Actions of insulin-like growth factors. Annu Rev Physiol. 1985;47:443–467. doi: 10.1146/annurev.ph.47.030185.002303. [DOI] [PubMed] [Google Scholar]
- Giudice L. C., Farrell E. M., Pham H., Lamson G., Rosenfeld R. G. Insulin-like growth factor binding proteins in maternal serum throughout gestation and in the puerperium: effects of a pregnancy-associated serum protease activity. J Clin Endocrinol Metab. 1990 Oct;71(4):806–816. doi: 10.1210/jcem-71-4-806. [DOI] [PubMed] [Google Scholar]
- Hancock K., Tsang V. C. India ink staining of proteins on nitrocellulose paper. Anal Biochem. 1983 Aug;133(1):157–162. doi: 10.1016/0003-2697(83)90237-3. [DOI] [PubMed] [Google Scholar]
- Hassager C., Fitzpatrick L. A., Spencer E. M., Riggs B. L., Conover C. A. Basal and regulated secretion of insulin-like growth factor binding proteins in osteoblast-like cells is cell line specific. J Clin Endocrinol Metab. 1992 Jul;75(1):228–233. doi: 10.1210/jcem.75.1.1377704. [DOI] [PubMed] [Google Scholar]
- Hossenlopp P., Segovia B., Lassarre C., Roghani M., Bredon M., Binoux M. Evidence of enzymatic degradation of insulin-like growth factor-binding proteins in the 150K complex during pregnancy. J Clin Endocrinol Metab. 1990 Oct;71(4):797–805. doi: 10.1210/jcem-71-4-797. [DOI] [PubMed] [Google Scholar]
- Hossenlopp P., Seurin D., Segovia-Quinson B., Hardouin S., Binoux M. Analysis of serum insulin-like growth factor binding proteins using western blotting: use of the method for titration of the binding proteins and competitive binding studies. Anal Biochem. 1986 Apr;154(1):138–143. doi: 10.1016/0003-2697(86)90507-5. [DOI] [PubMed] [Google Scholar]
- Jones J. I., D'Ercole A. J., Camacho-Hubner C., Clemmons D. R. Phosphorylation of insulin-like growth factor (IGF)-binding protein 1 in cell culture and in vivo: effects on affinity for IGF-I. Proc Natl Acad Sci U S A. 1991 Sep 1;88(17):7481–7485. doi: 10.1073/pnas.88.17.7481. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kiefer M. C., Masiarz F. R., Bauer D. M., Zapf J. Identification and molecular cloning of two new 30-kDa insulin-like growth factor binding proteins isolated from adult human serum. J Biol Chem. 1991 May 15;266(14):9043–9049. [PubMed] [Google Scholar]
- LaTour D., Mohan S., Linkhart T. A., Baylink D. J., Strong D. D. Inhibitory insulin-like growth factor-binding protein: cloning, complete sequence, and physiological regulation. Mol Endocrinol. 1990 Dec;4(12):1806–1814. doi: 10.1210/mend-4-12-1806. [DOI] [PubMed] [Google Scholar]
- Lee Y. L., Hintz R. L., James P. M., Lee P. D., Shively J. E., Powell D. R. Insulin-like growth factor (IGF) binding protein complementary deoxyribonucleic acid from human HEP G2 hepatoma cells: predicted protein sequence suggests an IGF binding domain different from those of the IGF-I and IGF-II receptors. Mol Endocrinol. 1988 May;2(5):404–411. doi: 10.1210/mend-2-5-404. [DOI] [PubMed] [Google Scholar]
- Mohan S., Bautista C. M., Wergedal J., Baylink D. J. Isolation of an inhibitory insulin-like growth factor (IGF) binding protein from bone cell-conditioned medium: a potential local regulator of IGF action. Proc Natl Acad Sci U S A. 1989 Nov;86(21):8338–8342. doi: 10.1073/pnas.86.21.8338. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Neely E. K., Rosenfeld R. G. Insulin-like growth factors (IGFs) reduce IGF-binding protein-4 (IGFBP-4) concentration and stimulate IGFBP-3 independently of IGF receptors in human fibroblasts and epidermal cells. Endocrinology. 1992 Feb;130(2):985–993. doi: 10.1210/endo.130.2.1370799. [DOI] [PubMed] [Google Scholar]
- Nissley P., Lopaczynski W. Insulin-like growth factor receptors. Growth Factors. 1991;5(1):29–43. doi: 10.3109/08977199109000269. [DOI] [PubMed] [Google Scholar]
- Orlowski C. C., Ooi G. T., Rechler M. M. Dexamethasone stimulates transcription of the insulin-like growth factor-binding protein-1 gene in H4-II-E rat hepatoma cells. Mol Endocrinol. 1990 Oct;4(10):1592–1599. doi: 10.1210/mend-4-10-1592. [DOI] [PubMed] [Google Scholar]
- Perkel V. S., Mohan S., Baylink D. J., Linkhart T. A. An inhibitory insulin-like growth factor binding protein (In-IGFBP) from human prostatic cell conditioned medium reveals N-terminal sequence identity with bone derived In-IGFBP. J Clin Endocrinol Metab. 1990 Aug;71(2):533–535. doi: 10.1210/jcem-71-2-533. [DOI] [PubMed] [Google Scholar]
- Powell D. R., Suwanichkul A., Cubbage M. L., DePaolis L. A., Snuggs M. B., Lee P. D. Insulin inhibits transcription of the human gene for insulin-like growth factor-binding protein-1. J Biol Chem. 1991 Oct 5;266(28):18868–18876. [PubMed] [Google Scholar]
- Rosenfeld R. G., Dollar L. A. Characterization of the somatomedin-C/insulin-like growth factor I (SM-C/IGF-I) receptor on cultured human fibroblast monolayers: regulation of receptor concentrations by SM-C/IGF-I and insulin. J Clin Endocrinol Metab. 1982 Sep;55(3):434–440. doi: 10.1210/jcem-55-3-434. [DOI] [PubMed] [Google Scholar]
- Rosenfeld R. G., Lamson G., Pham H., Oh Y., Conover C., De Leon D. D., Donovan S. M., Ocrant I., Giudice L. Insulinlike growth factor-binding proteins. Recent Prog Horm Res. 1990;46:99–163. doi: 10.1016/b978-0-12-571146-3.50009-2. [DOI] [PubMed] [Google Scholar]
- Shimasaki S., Uchiyama F., Shimonaka M., Ling N. Molecular cloning of the cDNAs encoding a novel insulin-like growth factor-binding protein from rat and human. Mol Endocrinol. 1990 Oct;4(10):1451–1458. doi: 10.1210/mend-4-10-1451. [DOI] [PubMed] [Google Scholar]
- Unterman T. G., Oehler D. T., Murphy L. J., Lacson R. G. Multihormonal regulation of insulin-like growth factor-binding protein-1 in rat H4IIE hepatoma cells: the dominant role of insulin. Endocrinology. 1991 Jun;128(6):2693–2701. doi: 10.1210/endo-128-6-2693. [DOI] [PubMed] [Google Scholar]
- Wood W. I., Cachianes G., Henzel W. J., Winslow G. A., Spencer S. A., Hellmiss R., Martin J. L., Baxter R. C. Cloning and expression of the growth hormone-dependent insulin-like growth factor-binding protein. Mol Endocrinol. 1988 Dec;2(12):1176–1185. doi: 10.1210/mend-2-12-1176. [DOI] [PubMed] [Google Scholar]










