Paxillin localizes to the lymphocyte microtubule organizing center and associates with the microtubule cytoskeleton.

Paxillin associates with the microtubule cytoskeleton and the immunological synapse of CTL through its leucine-aspartic acid domains and contributes to microtubule organizing center reorientation.

The cytoskeletal adaptor protein paxillin localizes to the microtubule organizing center (MTOC) in T cells and, upon target cell binding, is recruited to the supramolecular activation complex (SMAC). We mapped the region of paxillin that associates with both the MTOC and SMAC to the leucine-aspartic acid (LD) domains and showed that a protein segment containing LD2-4 was sufficient for MTOC and...

LARG and mDia1 Link G 12/13 to Cell Polarity and Microtubule Dynamics

Regulation of cell polarity is a process observed in all cells. During directed migration, cells orientate their microtubule cytoskeleton and the microtubule-organizing-center (MTOC), which involves integrins and downstream Cdc42 and glycogen synthase kinase-3 activity. However, the contribution of G protein-coupled receptor signal transduction for MTOC polarity is less well understood. Here, w...

Domains and Contributes to Microtubule of CTL through Its Leucine-Aspartic Acid Synapse Cytoskeleton and the Immunological Paxillin Associates with the Microtubule

A role for phosphatidylinositol 3-kinase in TCR-stimulated ERK activation leading to paxillin phosphorylation and CTL degranulation.

PI3K is an important regulator of a number of cellular processes. We examined the contribution of PI3K to mouse CTL signaling, leading to degranulation. We show that TCR-triggered, but not phorbol ester and calcium ionophore-induced, CTL degranulation is dependent on PI3K activity. Although PI3K activity is required for optimal LFA-1-mediated adhesion and cell spreading, this most likely does n...

The Rap1-cofilin-1 pathway coordinates actin reorganization and MTOC polarization at the B cell immune synapse.

B cells that bind antigens displayed on antigen-presenting cells (APCs) form an immune synapse, a polarized cellular structure that optimizes the dual functions of the B cell receptor (BCR), signal transduction and antigen internalization. Immune synapse formation involves polarization of the microtubule-organizing center (MTOC) towards the APC. We now show that BCR-induced MTOC polarization re...