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Articles 1 - 4 of 4
Full-Text Articles in Cell and Developmental Biology
Integrin (Alpha 6 Beta 4) Regulation Of Eif-4e Activity And Vegf Translation: A Survival Mechanism For Carcinoma Cells, Jun Chung, Robin E. Bachelder, Elizabeth A. Lipscomb, Leslie M. Shaw, Arthur M. Mercurio
Integrin (Alpha 6 Beta 4) Regulation Of Eif-4e Activity And Vegf Translation: A Survival Mechanism For Carcinoma Cells, Jun Chung, Robin E. Bachelder, Elizabeth A. Lipscomb, Leslie M. Shaw, Arthur M. Mercurio
Arthur M. Mercurio
We define a novel mechanism by which integrins regulate growth factor expression and the survival of carcinoma cells. Specifically, we demonstrate that the alpha 6 beta 4 integrin enhances vascular endothelial growth factor (VEGF) translation in breast carcinoma cells. The mechanism involves the ability of this integrin to stimulate the phosphorylation and inactivation of 4E-binding protein (4E-BP1), a translational repressor that inhibits the function of eukaryotic translation initiation factor 4E (eIF-4E). The regulation of 4E-BP1 phosphorylation by alpha 6 beta 4 derives from the ability of this integrin to activate the PI-3K-Akt pathway and, consequently, the rapamycin-sensitive kinase mTOR that …
Regulation Of Cellular Interactions With Laminin By Integrin Cytoplasmic Domains: The A And B Structural Variants Of The Alpha 6 Beta 1 Integrin Differentially Modulate The Adhesive Strength, Morphology, And Migration Of Macrophages, Leslie M. Shaw, Arthur M. Mercurio
Regulation Of Cellular Interactions With Laminin By Integrin Cytoplasmic Domains: The A And B Structural Variants Of The Alpha 6 Beta 1 Integrin Differentially Modulate The Adhesive Strength, Morphology, And Migration Of Macrophages, Leslie M. Shaw, Arthur M. Mercurio
Arthur M. Mercurio
Several integrin alpha subunits have structural variants that are identical in their extracellular and transmembrane domains but that differ in their cytoplasmic domains. The functional significance of these variants, however, is unknown. In the present study, we examined the possibility that the A and B variants of the alpha 6 beta 1 integrin laminin receptor differ in function. For this purpose, we expressed the alpha 6A and alpha 6B cDNAs, as well as a truncated alpha 6 cDNA (alpha 6-delta CYT) in which the cytoplasmic domain sequence was deleted after the GFFKR pentapeptide, in P388D1 cells, an alpha 6 deficient …
Endothelial Cells Assemble Two Distinct Alpha6beta4-Containing Vimentin-Associated Structures: Roles For Ligand Binding And The Beta4 Cytoplasmic Tail, Suzanne M. Homan, Arthur M. Mercurio, Susan E. Laflamme
Endothelial Cells Assemble Two Distinct Alpha6beta4-Containing Vimentin-Associated Structures: Roles For Ligand Binding And The Beta4 Cytoplasmic Tail, Suzanne M. Homan, Arthur M. Mercurio, Susan E. Laflamme
Arthur M. Mercurio
The alpha6beta4 laminin binding integrin functions in the assembly of type I hemidesmosomes, which are specialized cell-matrix adhesion sites found in stratified epithelial cells. Although endothelial cells do not express all the components of type I hemidesmosomes, endothelial cells can express the alpha6beta4 integrin. Because endothelial cells lose expression of alpha6beta4 in culture, we expressed recombinant alpha6beta4 in the dermal microvascular endothelial cell line, HMEC-1, to test whether endothelial cells can assemble adhesion structures containing alpha6beta4. Using immunofluorescence microscopy, we found that recombinant alpha6beta4 concentrates specifically in a novel fibrillar structure on the basal surface of endothelial cells in the …
Regulation Of Alpha 6 Beta 1 Integrin Laminin Receptor Function By The Cytoplasmic Domain Of The Alpha 6 Subunit, Leslie M. Shaw, Arthur M. Mercurio
Regulation Of Alpha 6 Beta 1 Integrin Laminin Receptor Function By The Cytoplasmic Domain Of The Alpha 6 Subunit, Leslie M. Shaw, Arthur M. Mercurio
Arthur M. Mercurio
The alpha 6 beta 1 integrin is expressed on the macrophage surface in an inactive state and requires cellular activation with PMA or cytokines to function as a laminin receptor (Shaw, L. M., J. M. Messier, and A. M. Mercurio. 1990. J. Cell Biol. 110:2167-2174). In the present study, the role of the alpha 6 subunit cytoplasmic domain in alpha 6 beta 1 integrin activation was examined. The use of P388D1 cells, an alpha 6-integrin deficient macrophage cell line, facilitated this analysis because expression of either the alpha 6A or alpha 6B subunit cDNAs restores their activation responsive laminin adhesion …