Actin polymerization controls the activation of multidrug efflux at fertilization by translocation and fine-scale positioning of ABCB1 on microvilli.

ABSTRACT: Fertilization changes the structure and function of the cell surface. In sea urchins, these changes include polymerization of cortical actin and a coincident, switch-like increase in the activity of the multidrug efflux transporter ABCB1a. However, it is not clear how cortical reorganization leads to changes in membrane transport physiology. In this study, we used three-dimensional superresolution fluorescence microscopy to resolve the fine-scale movements of the transporter along polymerizing actin filaments, and we show that efflux activity is established after ABCB1a translocates to the tips of the microvilli. Inhibition of actin polymerization or bundle formation prevents tip localization, resulting in the patching of ABCB1a at the cell surface and decreased efflux activity. In contras

SUBMITTER: Whalen K 

PROVIDER: S-EPMC3442413 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature