Through its many ligand-binding functions, the insulin-like growth factor Il/mannose 6-phosphate receptor (IGF2R) is responsible for transporting mannose-6-phosphate (Man-6-P)-bearing lysosomal enzymes to their appropriate intracellular destination, for mediating uptake and subsequent degradation of the mitogen, insulin-like growth factor 11 (IGF-II), and for facilitating activation of the growth inhibitor, transforming growth factor-b (TGF-b). Each of these activities is consistent with the proposed role of the IGF2R as a tumor suppressor, yet the question of which ligand-binding functions of the IGF2R are responsible for the cell-growth suppressor activity have not been directly addressed. This project will test the hypothesis that the IGF2R's growth suppressor activity depends on the efficient operation of both its IGF-II and Man-6-F binding functions, by the following specific aims: 1) To measure the growth-suppressive effects of wild-type IGF2R vs. receptors mutated in the Man-6-P vs. IGF-II binding functions. IGF2R-deficient cell lines transfected with wild-type IGF2R cDNA expression constructs or IGF2R mutants defective in binding IGF-II or Man-6-P ligands will be analyzed for proliferation relative to vector-transfected controls. Our expectation is that increased wild-type IGF2R expression will inhibit cell growth, and that the mutants will show impairment of this growth-suppressive activity. 2) To determine the effects of cancer-associated M6P/IGF2R missense or truncation mutations on the growth-suppressive activity of the IGF2R. We expect that missense mutations will exhibit reductions in IGF2R function and that truncation mutants may have novel dominant-negative effects. 3) To assess the contribution to the receptor's growth-suppressive activity of pre- and post-receptor binding events that depend on IGF2R dimerization, i.e. development of high-affinity ligand binding and enhanced internalization. These studies will contribute to understanding the receptor's tumor suppressor function and permit rational design of strategies that exploit the IGF2R in cancer prevention and therapy.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA091885-02
Application #
6515149
Study Section
Endocrinology Study Section (END)
Program Officer
Freeman, Colette S
Project Start
2001-07-01
Project End
2005-06-30
Budget Start
2002-07-01
Budget End
2003-06-30
Support Year
2
Fiscal Year
2002
Total Cost
$165,375
Indirect Cost
Name
University of Nebraska Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
City
Omaha
State
NE
Country
United States
Zip Code
68198
Fei, Xiang; Zavorka, Megan E; Malik, Guillaume et al. (2017) General Linker Diversification Approach to Bivalent Ligand Assembly: Generation of an Array of Ligands for the Cation-Independent Mannose 6-Phosphate Receptor. Org Lett 19:4267-4270
Wang, Y; MacDonald, R G; Thinakaran, G et al. (2017) Insulin-Like Growth Factor-II/Cation-Independent Mannose 6-Phosphate Receptor in Neurodegenerative Diseases. Mol Neurobiol 54:2636-2658
Zavorka, Megan E; Connelly, Christopher M; Grosely, Rosslyn et al. (2016) Inhibition of insulin-like growth factor II (IGF-II)-dependent cell growth by multidentate pentamannosyl 6-phosphate-based ligands targeting the mannose 6-phosphate/IGF-II receptor. Oncotarget 7:62386-62410
Wang, Y; Buggia-Prévot, V; Zavorka, M E et al. (2015) Overexpression of the Insulin-Like Growth Factor II Receptor Increases ?-Amyloid Production and Affects Cell Viability. Mol Cell Biol 35:2368-84
Kreiling, Jodi L; Montgomery, Michelle A; Wheeler, Joseph R et al. (2012) Dominant-negative effect of truncated mannose 6-phosphate/insulin-like growth factor II receptor species in cancer. FEBS J 279:2695-713
Hartman, Michelle A; Kreiling, Jodi L; Byrd, James C et al. (2009) High-affinity ligand binding by wild-type/mutant heteromeric complexes of the mannose 6-phosphate/insulin-like growth factor II receptor. FEBS J 276:1915-29
Fei, Xiang; Connelly, Christopher M; MacDonald, Richard G et al. (2008) A set of phosphatase-inert ""molecular rulers"" to probe for bivalent mannose 6-phosphate ligand-receptor interactions. Bioorg Med Chem Lett 18:3085-9
Hawkes, C; Amritraj, A; Macdonald, R G et al. (2007) Heterotrimeric G proteins and the single-transmembrane domain IGF-II/M6P receptor: functional interaction and relevance to cell signaling. Mol Neurobiol 35:329-45
Charette, Bradley D; Macdonald, Richard G; Wetzel, Stefan et al. (2006) Protein structure similarity clustering: dynamic treatment of PDB structures facilitates clustering. Angew Chem Int Ed Engl 45:7766-70
Hawkes, Cheryl; Jhamandas, Jack H; Harris, Kim H et al. (2006) Single transmembrane domain insulin-like growth factor-II/mannose-6-phosphate receptor regulates central cholinergic function by activating a G-protein-sensitive, protein kinase C-dependent pathway. J Neurosci 26:585-96

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