Integrins are a widely distributed supergene family of integral membrane proteins currently comprised of 15 members which mediate cell/cell and cell/substratum interactions. Integrins play important roles in the immune response, lymphocyte targeting, regulation of metalloproteinase genes, and in the migratory and invasive properties of cells, and therefore may be diagnostic and therapeutic targets in rheumatic disease. Continued support is requested for molecular analysis of the ligand binding to B3 integrins. This will be achieved by site directed and random mutagenesis of regions of the B3 integrins critical to ligand binding function. The functions of these mutants, when transiently expressed in COS cells or in stable cell lines in Chinese hamster ovary cells, will be evaluated by; 1) conformation specific monoclonal antibodies which preferentially recognize occupied forms of B3 integrins, 2) binding of fluorescent latex beads bearing bound adhesive proteins, and 3) quantitative binding of ligands to purified integrins in vitro. The alpha subunits control ligand recognition specificity of integrins. Domain """"""""swapping"""""""" experiments will pinpoint regions which control this specificity. Additional regions of integrins involved in ligand recognition will be identified by sequencing of naturally occurring mutants of B3 integrins by use of polymerase chain reaction. Novel regions identified in this way will be subjected to the same intensive mutagenic analysis proposed for the already identified regions. A second proposed method of identification of novel regions of integrins involved in recognition function is by scanning linker mutagenesis with selection by conformation specific antibodies. A complementary strategy will be to prepare synthetic peptides from regions of integrins thought to be involved in ligand binding, to evaluate the capacity of these peptides to inhibit ligand binding, and to bind the ligands themselves. Monoclonal antibodies against these peptides will also be used as probes of the ligand recognition site. These studies will provide a detailed molecular analysis of ligand binding regions of prototype integrins, and will provide fundamental information concerning ligand recognition by all integrins.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AR027214-19
Application #
2837523
Study Section
Special Emphasis Panel (NSS)
Program Officer
Serrate-Sztein, Susana
Project Start
1980-08-01
Project End
2000-11-30
Budget Start
1998-12-01
Budget End
1999-11-30
Support Year
19
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Zou, Wei; Izawa, Takashi; Zhu, Tingting et al. (2013) Talin1 and Rap1 are critical for osteoclast function. Mol Cell Biol 33:830-44
Cantor, Joseph M; Ginsberg, Mark H (2012) CD98 at the crossroads of adaptive immunity and cancer. J Cell Sci 125:1373-82
Kim, Chungho; Schmidt, Thomas; Cho, Eun-Gyung et al. (2012) Basic amino-acid side chains regulate transmembrane integrin signalling. Nature 481:209-13
Ye, Feng; Kim, Chungho; Ginsberg, Mark H (2012) Reconstruction of integrin activation. Blood 119:26-33
Gutierrez, Edgar; Tkachenko, Eugene; Besser, Achim et al. (2011) High refractive index silicone gels for simultaneous total internal reflection fluorescence and traction force microscopy of adherent cells. PLoS One 6:e23807
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
Ring, Colleen; Ginsberg, Mark H; Haling, Jacob et al. (2011) Abl-interactor-1 (Abi1) has a role in cardiovascular and placental development and is a binding partner of the alpha4 integrin. Proc Natl Acad Sci U S A 108:149-54
Tkachenko, Eugene; Sabouri-Ghomi, Mohsen; Pertz, Olivier et al. (2011) Protein kinase A governs a RhoA-RhoGDI protrusion-retraction pacemaker in migrating cells. Nat Cell Biol 13:660-7
Cantor, Joseph; Slepak, Marina; Ege, Nil et al. (2011) Loss of T cell CD98 H chain specifically ablates T cell clonal expansion and protects from autoimmunity. J Immunol 187:851-60
Kummer, Christiane; Petrich, Brian G; Rose, David M et al. (2010) A small molecule that inhibits the interaction of paxillin and alpha 4 integrin inhibits accumulation of mononuclear leukocytes at a site of inflammation. J Biol Chem 285:9462-9

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