Journal of Clinical Endocrinology & Metabolism, Vol 67, 669-675, Copyright © 1988 by Endocrine Society

ARTICLES

The insulin-like growth factor II/mannose-6-phosphate receptor is present in monkey serum

MC Gelato, W Kiess, L Lee, S Malozowski, MM Rechler and P Nissley
Metabolism Branch, National Cancer Institute, Bethesda, Maryland 20892.

We recently reported that the insulin-like growth factor II (IGF- II)/mannose-6-phosphate (Man-6-P) receptor is present in fetal and postnatal rat serum and that its serum content declined dramatically postnatally between days 20 and 40 . We now provide evidence that the IGF-II/Man-6-P receptor is also present in monkey serum. Serum was gel filtered on Sephadex G-200, and the column fractions were assayed for binding of radiolabeled IGF-II. There was significant binding of [125I]IGF-II to the void volume fractions in addition to binding to the 150K and 40K carrier proteins. Binding to the void volume fractions was greatest in cord serum and decreased with age. Competitive binding studies with [125I]IGF-II and the void volume pools from monkey serum demonstrated that IGF-I competed less potently than IGF-II, and insulin did not compete. Radiolabeled IGF-I did not bind specifically to the void volume pools. Chemical cross-linking of [125I]IGF-II to aliquots of the void volume pools from monkey cord serum samples and analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of dithiothreitol demonstrated a specific band at about 240K. Western blotting using a specific antiserum (no. 3637) against rat IGF- II/Man-6-P receptor was performed on aliquots of the Sephadex G-200 void volume pools of monkey serum. A band of approximately the same size as that found with human fibroblast members (approximately 215 K without dithiothreitol) was detected. The IGF-II/Man-6-P receptor band was more intense in cord serum than in the postnatal samples. When cord serum Sephadex G-200 pools were gel filtered on Sephadex G-50 in 1 mol/L acetic acid to separate binding components from free IGF, and IGF- II was measured by RRA, approximately 20% of the circulating IGF-II was found to be associated with this IGF-II/Man-6-P receptor in monkey serum. We conclude that the IGF-II/Man-6-P receptor present in serum may be a significant carrier for IGF-II in the monkey.

This article has been cited by other articles:

				M.L. Macpherson, R.C.M. Simmen, F.A. Simmen, J. Hernandez, B.R. Sheerin, D.D. Varner, P. Loomis, M.E. Cadario, C.D. Miller, S.P. Brinsko, et al. Insulin-Like Growth Factor-I and Insulin-Like Growth Factor Binding Protein-2 and -5 in Equine Seminal Plasma: Association with Sperm Characteristics and Fertility Biol Reprod, August 1, 2002; 67(2): 648 - 654. [Abstract] [Full Text] [PDF]

				L. Poretsky, N. A. Cataldo, Z. Rosenwaks, and L. C. Giudice The Insulin-Related Ovarian Regulatory System in Health and Disease Endocr. Rev., August 1, 1999; 20(4): 535 - 582. [Abstract] [Full Text] [PDF]

				M. Costello, R. C. Baxter, and C. D. Scott Regulation of Soluble Insulin-Like Growth Factor II/Mannose 6-Phosphate Receptor in Human Serum: Measurement by Enzyme-Linked Immunosorbent Assay J. Clin. Endocrinol. Metab., February 1, 1999; 84(2): 611 - 617. [Abstract] [Full Text]

				K. J. Valenzano, E. Heath-Monnig, S. E. Tollefsen, M. Lake, and P. Lobel Biophysical and Biological Properties of Naturally Occurring High Molecular Weight Insulin-like Growth Factor II Variants J. Biol. Chem., February 21, 1997; 272(8): 4804 - 4813. [Abstract] [Full Text] [PDF]

				K. J. Valenzano, J. Remmler, and P. Lobel Soluble Insulin-like Growth Factor II/Mannose 6-Phosphate Receptor Carries Multiple High Molecular Weight Forms of Insulin-like Growth Factor II in Fetal Bovine Serum J. Biol. Chem., July 7, 1995; 270(27): 16441 - 16448. [Abstract] [Full Text] [PDF]

				J. C. Byrd, J. H. Y. Park, B. S. Schaffer, F. Garmroudi, and R. G. MacDonald Dimerization of the Insulin-like Growth Factor II/Mannose 6-Phosphate Receptor J. Biol. Chem., June 16, 2000; 275(25): 18647 - 18656. [Abstract] [Full Text] [PDF]

				J. Linnell, G. Groeger, and A. B. Hassan Real Time Kinetics of Insulin-like Growth Factor II (IGF-II) Interaction with the IGF-II/Mannose 6-Phosphate Receptor. THE EFFECTS OF DOMAIN 13 AND pH J. Biol. Chem., June 22, 2001; 276(26): 23986 - 23991. [Abstract] [Full Text] [PDF]