抄録
Various membrane molecules are sequestered to caveolae when cross-linked by antibodies or other multivalent ligands. One of the molecules, β2-microglobulin (β2m) in human fibroblasts, is known to line-up along actin filaments when bound with antibodies. In the present study we questioned whether other molecules show a similar distributional change before sequestration to caveolae. To compare with the anti-β2m antibody, two probes were used: cholera toxin B subunit (CTX-B), which binds to ganglioside GM1, and biotinylated and nicked θ-toxin (BC θ), which recognizes raft cholesterol. BCθ showed a tendency to line-up longitudinally, which was similar to, but less obvious than the anti-β2m antibody. In contrast, CTX-B did not show any sign of linear arrangement. Despite the difference, the anti-β2m antibody and CTX-B eventually concentrated to caveolae and were incorporated into the same endo-lysosomal compartment. The result suggests that cross-linked plasma membrane molecules take two different routes to caveolae, one along actin filaments and the other independent of them.
