The major objective of this project is to conduct in depth studies of the molecular mechanisms underlying cellular adhesion to the extracellular matrix. This will be accomplished by investigating the structure, function and biological properties of vitronectin receptor (VNR), a member of the integrin family of cell adhesion receptors. Integrins are expressed on virtually all cells examined from slime mold to man and mediate a divalent cation-dependent cellular adhesion to a wide variety of adhesive proteins present in the extracellular matrix. Structurally, integrins are heterodimes composed of one of three beta subunits with as many as 10 different alpha subunits. A number of integrins have ligand binding properties which depend on the recognition of the Arg-Gly-Asp (RGD) sequence in one or more adhesive proteins. In this regard, we have recently isolated an integrin termed VNR-1, from human endothelial and melanoma cells which binds vitronectin, fibrinogen and von Willebrand factor in an RGD-dependent manner. One of the goals of this proposal will be to define the minimal structural requirements for VNR's recognition of RGD-containing matrix components and to characterize the divalent cation regulation of this interaction. These studies will focus on receptor-ligand interactions involving VNR in solution, in liposomes and on the cell surface. We have recently isolated a novel member of the integrin family which shares some features with VNR-1. This receptor is expressed on cells of epithelial origin and is characterized by an antigenically similar alpha subunit to that present on VNR-1. Cells that express VNR-2 attach to vitronectin but fail to recognize fibrinogen or von Willebrand factor suggesting that this receptor is functionally distinct from vNR-1. Therefore, we will apply knowledge gained for VNR-1 to investigate the structure and function of VNR-2. This approach will attempt to explain the molecular differences between these integrins that accounts for their functional differences. This will be accomplished by initially comparing the primary sequences of VNR-1 and VNR-2, followed by a molecular approach using site-directed mutagenesis to identify functional sites and to exchange subunits between cells expressing either receptor by cDNA- mediated gene transfer. The approaches outlined in this project should provide basic molecular and cell biological information pertaining to the structure, function and regulation of integrin-dependent cell recognition of the extracellular matrix, thus furthering our understanding of the molecular mechanisms underlying cellular adhesion.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
7R01CA050286-04
Application #
3194702
Study Section
Pathobiochemistry Study Section (PBC)
Project Start
1989-08-01
Project End
1994-05-31
Budget Start
1992-06-01
Budget End
1993-05-31
Support Year
4
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Wang, Huawei; Lapek, John; Fujimura, Ken et al. (2018) Pseudopodium-enriched atypical kinase 1 mediates angiogenesis by modulating GATA2-dependent VEGFR2 transcription. Cell Discov 4:26
Advani, Sunil J; Camargo, Maria Fernanda; Seguin, Laetitia et al. (2015) Kinase-independent role for CRAF-driving tumour radioresistance via CHK2. Nat Commun 6:8154
Westenskow, Peter D; Kurihara, Toshihide; Aguilar, Edith et al. (2013) Ras pathway inhibition prevents neovascularization by repressing endothelial cell sprouting. J Clin Invest 123:4900-8
Weis, Sara M; Cheresh, David A (2011) ?V integrins in angiogenesis and cancer. Cold Spring Harb Perspect Med 1:a006478
Schmid, Michael C; Avraamides, Christie J; Dippold, Holly C et al. (2011) Receptor tyrosine kinases and TLR/IL1Rs unexpectedly activate myeloid cell PI3k?, a single convergent point promoting tumor inflammation and progression. Cancer Cell 19:715-27
Anand, Sudarshan; Majeti, Bharat K; Acevedo, Lisette M et al. (2010) MicroRNA-132-mediated loss of p120RasGAP activates the endothelium to facilitate pathological angiogenesis. Nat Med 16:909-14
Desgrosellier, Jay S; Cheresh, David A (2010) Integrins in cancer: biological implications and therapeutic opportunities. Nat Rev Cancer 10:9-22
Acevedo, Lisette M; Barillas, Samuel; Weis, Sara M et al. (2008) Semaphorin 3A suppresses VEGF-mediated angiogenesis yet acts as a vascular permeability factor. Blood 111:2674-80
Weis, Sara M; Lim, Ssang-Taek; Lutu-Fuga, Kimberly M et al. (2008) Compensatory role for Pyk2 during angiogenesis in adult mice lacking endothelial cell FAK. J Cell Biol 181:43-50
Weis, Sara M; Lindquist, Jeffrey N; Barnes, Leo A et al. (2007) Cooperation between VEGF and beta3 integrin during cardiac vascular development. Blood 109:1962-70

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