Journal d'imagerie et de dynamique moléculaires
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Abstrait

Migration of leukocytes is controlled by actin flow direction

Branchini Huta

The integrin lymphocyte function-associated antigen-1 (LFA-1, L2) is involved in a variety of sticky contacts, including antigen recognition, vascular emigration, and leukocyte movement within tissues. The extended-open conformation of integrin ectodomains binds ligand with 1,000-fold higher affinity than the bent-closed and extended-closed conformations. The binding of LFA-1 to ICAM ligands by the I domain in the integrin head is conveyed to the actin cytoskeleton through the -subunit leg, transmembrane, and cytoplasmic domains via adaptors like talins and kindlins that bind particular locations in the -subunit cytoplasmic domain. Measurements of traction force on substrates, as well as more detailed measurements of force within ligands and cytoskeletal components, have suggested that integrins transmit force between extracellular ligands and the actin cytoskeleton, as discussed. In the 1-6 pN range, forces on the cytoplasmic domain of the LFA-1 2-subunit have been quantified and linked to ligand binding and the cytoskeleton.