{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,21]],"date-time":"2026-02-21T02:23:39Z","timestamp":1771640619631,"version":"3.50.1"},"reference-count":31,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2005,2,4]],"date-time":"2005-02-04T00:00:00Z","timestamp":1107475200000},"content-version":"vor","delay-in-days":5301,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal Cellular Physiology"],"published-print":{"date-parts":[[1990,8]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The cell surface of human fibroblasts contains not only type IIGF receptors but at least two forms of IGFBPs. Studies were undertaken to analyze the mechanisms by which these IGFBPs alter IGF\u2010I\u2010cell surface interactions. Human fetal fibroblasts (GM10) and a human glioblastoma cell line (1690) were chosen for analysis. During assays to quantify [<jats:sup>125<\/jats:sup>l]\u2010IGF\u2010l binding, both cell lines were shown to release IGFBPs into the binding assay buffer. Under equilibrium conditions, [<jats:sup>125<\/jats:sup>I]\u2010IGF\u2010I preferentially associates with IGFBPs in the assay buffer (up to 40% of the [<jats:sup>125<\/jats:sup>I]\u2010IGF\u2010I added) since they have a higher affinity than type IIGF receptors or IGFBPs associated with the cell surface. Likewise the addition of increasing concentrations of unlabeled IGF\u2010I results in preferential competition for binding to assay buffer IGFBPs. This results in a repartitioning of the [<jats:sup>125<\/jats:sup>I]\u2010IGF\u2010I that is bound to assay buffer IGFBPs onto cell surface binding sites. The degree of repartitioning is quantitatively related to the amount of [<jats:sup>125<\/jats:sup>I]\u2010IGF\u2010I bound to released IGFBPs. When cultures are exposed to cycloheximide before the binding assay, both the amount of IGFBPs that are released into the assay buffer and the amount of [<jats:sup>125<\/jats:sup> I]\u2010IGF\u2010l that is repartitioned are decreased. In contrast when [Gln<jats:sup>3<\/jats:sup>, Ala<jats:sup>4<\/jats:sup>, Tyr<jats:sup>15<\/jats:sup>, Leu<jats:sup>16<\/jats:sup>]\u2010IGF\u2010l (IQAYLj\u2010IGF\u2010I, an IGF analog that has unaltered affinity for type I IGF receptors) is iodinated and tested, the competition curve with unlabeled IGF\u2010I shows no repartitioning effect. This form of IGF can be used to quantify type I receptor number independent of the presence of IGFBPs. IGF\u2010I and the [QAYL]\u2010IGF\u2010I compete equally with the [<jats:sup>125<\/jats:sup>I]\u2010[QAYL]\u2010IGF\u2010I for binding to cell surfaces, whereas unlabeled [QAYL]\u2010IGF\u2010I is &gt; 25\u2010fold less potent compared to IGF\u2010I in competing with [<jats:sup>125<\/jats:sup>I]\u2010IGF\u2010I for cell surface binding. Specific binding of [<jats:sup>125<\/jats:sup>I]\u2010[QAYL]\u2010IGF\u2010I to GM10 and 1690 cell surfaces is &lt; 20% of [<jats:sup>125<\/jats:sup>I]\u2010IGF\u2010I binding. These findings suggest that IGFBPs that are present on human fibroblast surfaces represent a large portion of the IGF binding sites. We conclude that the amount of IGFBPs released into assay buffer is a major determinant of the repartitioning of [<jats:sup>125<\/jats:sup>I]\u2010IGF\u2010I to cell surface binding sites and that both cell surface and assay buffer IGFBPs modulate type I IGF receptor binding.<\/jats:p>","DOI":"10.1002\/jcp.1041440210","type":"journal-article","created":{"date-parts":[[2005,2,26]],"date-time":"2005-02-26T09:03:20Z","timestamp":1109408600000},"page":"244-253","source":"Crossref","is-referenced-by-count":92,"title":["Insulin\u2010like growth factor (IGF) binding to human fibroblast and glioblastoma cells: The modulating effect of cell released IGF binding proteins (IGFBPs)"],"prefix":"10.1002","volume":"144","author":[{"given":"R. H.","family":"McCusker","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C.","family":"Camacho\u2010Hubner","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D. R.","family":"Clemmons","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M. L.","family":"Bayne","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M. A.","family":"Cascieri","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2005,2,4]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1042\/bj2490721"},{"key":"e_1_2_1_3_1","doi-asserted-by":"crossref","first-page":"6233","DOI":"10.1016\/S0021-9258(18)68777-0","article-title":"Structural analogues of human insulin like growth factor one with reduced affinity for serum biriding protein and the type II insulin like growth factor receptor","volume":"263","author":"Bayne M. L.","year":"1988","journal-title":"J. Biol. Chem."},{"key":"e_1_2_1_4_1","doi-asserted-by":"crossref","first-page":"15892","DOI":"10.1016\/S0021-9258(17)36342-1","article-title":"Distin biologically active receptors for insulin, insulin\u2010like growth factor and insulin\u2010like growth factor II in cultured skeletal muscle cells","volume":"260","author":"Beguinot F.","year":"1985","journal-title":"Biol. Chem."},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1159\/000180553"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0006-291X(88)80425-X"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/jcp.1041390125"},{"key":"e_1_2_1_8_1","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1093\/oxfordjournals.bmb.a072335","article-title":"Structural and functional analysis of insulin like growth factors","volume":"45","author":"Clemmons D. R.","year":"1989","journal-title":"Br. Med. Bull."},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1210\/jcem-63-4-996"},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1172\/JCI112470"},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1210\/mend-1-5-339"},{"key":"e_1_2_1_12_1","first-page":"190","volume-title":"Growth Hormone and Related Peptides","author":"D'Ercole A. J.","year":"1976"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0006-291X(88)80824-6"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1172\/JCI112343"},{"key":"e_1_2_1_15_1","first-page":"2122","article-title":"Somatomedin C receptors and longterm growth effects in human breast cells secreted in longterm cultures","volume":"44","author":"Furlanetto R.","year":"1984","journal-title":"Cancer Res."},{"key":"e_1_2_1_16_1","doi-asserted-by":"publisher","DOI":"10.1677\/joe.0.1200231"},{"key":"e_1_2_1_17_1","doi-asserted-by":"publisher","DOI":"10.1210\/endo-118-6-2555"},{"key":"e_1_2_1_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/0003-2697(86)90507-5"},{"key":"e_1_2_1_19_1","doi-asserted-by":"publisher","DOI":"10.1042\/bj2360417"},{"key":"e_1_2_1_20_1","doi-asserted-by":"publisher","DOI":"10.1210\/mend-3-7-1053"},{"key":"e_1_2_1_21_1","doi-asserted-by":"crossref","first-page":"8754","DOI":"10.1016\/S0021-9258(19)84446-0","article-title":"Insulin like growth factor binding protein from human plasma, purification and characterization","volume":"261","author":"Martin J. L.","year":"1986","journal-title":"J. Biol. Chem."},{"key":"e_1_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1002\/jcp.1041370316"},{"key":"e_1_2_1_23_1","doi-asserted-by":"crossref","first-page":"7795","DOI":"10.1016\/S0021-9258(18)83111-8","article-title":"Identification of the types of insulin like growth factor binding proteins that are secreted by muscle cells in vitro","volume":"264","author":"McCusker R. H.","year":"1989","journal-title":"J. Biol. Chem."},{"key":"e_1_2_1_24_1","doi-asserted-by":"publisher","DOI":"10.1210\/endo-125-2-867"},{"key":"e_1_2_1_25_1","doi-asserted-by":"publisher","DOI":"10.1002\/jcp.1041390304"},{"key":"e_1_2_1_26_1","doi-asserted-by":"publisher","DOI":"10.1210\/endo-122-5-2150"},{"key":"e_1_2_1_27_1","doi-asserted-by":"publisher","DOI":"10.1002\/jcp.1041210221"},{"key":"e_1_2_1_28_1","doi-asserted-by":"publisher","DOI":"10.1210\/jcem-66-1-173"},{"key":"e_1_2_1_29_1","doi-asserted-by":"publisher","DOI":"10.1021\/bi00545a027"},{"key":"e_1_2_1_30_1","doi-asserted-by":"publisher","DOI":"10.1172\/JCI110383"},{"key":"e_1_2_1_31_1","doi-asserted-by":"publisher","DOI":"10.1210\/mend-2-12-1176"},{"key":"e_1_2_1_32_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0300-595X(84)80006-7"}],"container-title":["Journal of Cellular Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fjcp.1041440210","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/jcp.1041440210","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,22]],"date-time":"2023-10-22T15:48:40Z","timestamp":1697989720000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/jcp.1041440210"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1990,8]]},"references-count":31,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1990,8]]}},"alternative-id":["10.1002\/jcp.1041440210"],"URL":"https:\/\/doi.org\/10.1002\/jcp.1041440210","archive":["Portico"],"relation":{},"ISSN":["0021-9541","1097-4652"],"issn-type":[{"value":"0021-9541","type":"print"},{"value":"1097-4652","type":"electronic"}],"subject":[],"published":{"date-parts":[[1990,8]]}}}