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Roles of microfilaments and microtubules in paxillin dynamics

Ying-Li Hu1, Jason H Haga, Hui Miao

  • 1Department of Bioengineering and the Whitaker Institute of Biomedical Engineering, University of California, San Diego, La Jolla, CA 92093, USA.

Biochemical and Biophysical Research Communications
|August 22, 2006
PubMed

Insights

Microfilaments and microtubules play distinct roles in paxillin dynamics within endothelial cells. Actin filaments are crucial for paxillin assembly in focal adhesions, while microtubules regulate its localization at the cell periphery.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Paxillin is a key signaling molecule at focal adhesions, involved in cell adhesion and migration.
  • The roles of the cytoskeleton, specifically microfilaments and microtubules, in regulating paxillin localization and phosphorylation are not fully understood.

Purpose of the Study:

  • To investigate the differential roles of microfilaments and microtubules in the localization and tyrosine phosphorylation of paxillin in bovine aortic endothelial cells (BAECs).
  • To elucidate the impact of cytoskeletal disruption on paxillin dynamics within focal adhesions.

Main Methods:

  • Treatment of BAECs with cytochalasin D (CD) to disrupt microfilaments.
  • Treatment of BAECs with colchicine and paclitaxol (taxol) to disrupt microtubules.
  • Analysis of paxillin localization, focal adhesion disassembly, and tyrosine phosphorylation.

Main Results:

  • Cytochalasin D inhibited paxillin tyrosine phosphorylation and caused focal adhesion disassembly and paxillin redistribution to the cytoplasm.
  • Colchicine and taxol disrupted peripheral focal adhesions, induced central reassembly, and slightly increased paxillin tyrosine phosphorylation.
  • Microfilaments are essential for overall paxillin assembly in focal adhesions, while microtubules are critical for peripheral and lamellipodial assembly.

Conclusions:

  • Actin filaments and microtubules play differential roles in the dynamic assembly and disassembly of paxillin at focal adhesions.
  • Tyrosine phosphorylation is an important component of paxillin dynamics within focal adhesions.

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