We have used an expression cloning strategy to isolate the cDNAs encoding the types III and II cell-surface receptors for transforming growth factor beta (TGF-beta). One major goal is to clone the multiple type I THP-1 cells, IEC-18 ras7 cells, and in HL-60 cells. Using the derived amino acid sequences of the types II and III receptors, we have generated anti-peptide sera that are specific for the encoded proteins. These reagents have allowed us to determine that the types of cell-surface TGF- beta binding-proteins expressed on a variety of human and animal tumors and cell lines that are or are not responsive to growth inhibition by TGF-beta is far more than previously appreciated. Thus a second major aim is to molecularly clone and characterize many of the other cell- surface TGF-beta receptors we and others have identified, and to study in detail their abilities to affect cell proliferation and gene expression. These include TGF-beta binding proteins attached to the plasma membrane through a glycosylphosphatidylinositol anchor, the major 70-74 kDa cell surface TGF-beta receptor in GH3 pituitary cells that also binds activin and inhibin, the major 38-kDa cell surface protein on several cells that binds TGF-beta2 at high affinity, and the about 50kDa proteins expressed on the surface of many cells that bind TGF-beta1, beta2, and beta3 with equal high affinity. As there are many cell- surface molecules that bind TGF-beta specifically, we need to understand how these several receptors interact with each other and with each other and with TGF-beta homo- and hetero-dimers, to understand why expression of certain receptor polypeptides enhances or inhibits binding of TGF-beta to other receptors, to determine the subcellular metabolism of the receptor polypeptides, and to determine whether receptor homo- or hetero- oligomerization is induced by TGF-beta and whether this is part of the signaling response. Finally, we and others have shown that a number of human tumor cell lines are resistant to growth-inhibition by TGF-beta and, as shown by affinity-labeling with [125I] TGF-beta, lack the type II and often other cell-surface receptors. We have shown, surprisingly, that several express mRNA encoding the type II TGF-beta receptor and that the encoded receptors contain the same point mutation in the predicted kinase domain, yet the cells express no surface receptor. We will clone and characterize these mutant receptor cDNAs, determine whether the mutations are functional and/or generate a dominant-negative phenotype, and cDNAs that we have and will clone. All of these studies are fundamental to our understanding of how TGF-beta exerts its multiple functions on a diverse array of cells, and in understanding how this novel class of cell-surface receptors transduces signals to the cell nucleus.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA063260-02
Application #
2105001
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1994-06-01
Project End
1998-03-31
Budget Start
1995-04-01
Budget End
1996-03-31
Support Year
2
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Whitehead Institute for Biomedical Research
Department
Type
DUNS #
076580745
City
Cambridge
State
MA
Country
United States
Zip Code
02142
Xiao, Zhan; Latek, Robert; Lodish, Harvey F (2003) An extended bipartite nuclear localization signal in Smad4 is required for its nuclear import and transcriptional activity. Oncogene 22:1057-69
Schiemann, William P; Blobe, Gerard C; Kalume, Dario E et al. (2002) Context-specific effects of fibulin-5 (DANCE/EVEC) on cell proliferation, motility, and invasion. Fibulin-5 is induced by transforming growth factor-beta and affects protein kinase cascades. J Biol Chem 277:27367-77
Blobe, G C; Schiemann, W P; Pepin, M C et al. (2001) Functional roles for the cytoplasmic domain of the type III transforming growth factor beta receptor in regulating transforming growth factor beta signaling. J Biol Chem 276:24627-37
Eischen, C M; Packham, G; Nip, J et al. (2001) Bcl-2 is an apoptotic target suppressed by both c-Myc and E2F-1. Oncogene 20:6983-93
Rodriguez, C; Huang, L J; Son, J K et al. (2001) Functional cloning of the proto-oncogene brain factor-1 (BF-1) as a Smad-binding antagonist of transforming growth factor-beta signaling. J Biol Chem 276:30224-30
Blobe, G C; Liu, X; Fang, S J et al. (2001) A novel mechanism for regulating transforming growth factor beta (TGF-beta) signaling. Functional modulation of type III TGF-beta receptor expression through interaction with the PDZ domain protein, GIPC. J Biol Chem 276:39608-17
Liu, X; Sun, Y; Weinberg, R A et al. (2001) Ski/Sno and TGF-beta signaling. Cytokine Growth Factor Rev 12:1-8
Xiao, Z; Watson, N; Rodriguez, C et al. (2001) Nucleocytoplasmic shuttling of Smad1 conferred by its nuclear localization and nuclear export signals. J Biol Chem 276:39404-10
Xiao, Z; Liu, X; Henis, Y I et al. (2000) A distinct nuclear localization signal in the N terminus of Smad 3 determines its ligand-induced nuclear translocation. Proc Natl Acad Sci U S A 97:7853-8
Blobe, G C; Schiemann, W P; Lodish, H F (2000) Role of transforming growth factor beta in human disease. N Engl J Med 342:1350-8

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