Control of efflux transporter activity by cell surface reorganization in embryos.

描述（由申请方提供）：本研究的总体目标是了解早期胚胎发育期间多药外排转运活性的细胞生物学调节。 该应用程序连接两个知识体系，多药外排转运的功能生理学，主要在癌症和上皮转运的背景下研究，以及细胞表面和膜组织的结构变化，主要在细胞和发育生物学的背景下研究。 在这项申请中，候选人将表征早期胚胎发育中发生的细胞表面变化与两种模式生物（海胆和小鼠）中外排转运蛋白活性的伴随变化之间的关系。 细胞生物学方面是了解运输活动如何通过细胞刺激迅速改变，特别是结构（移动到微绒毛）和功能（防止有毒物质进入细胞）之间的关系。 发育生物学方面是了解未受精卵的膜是如何从一个专门与精子融合的膜改变为现在保护和调节后续发育的膜。 该候选人的博士后研究揭示了海胆卵受精后ABCB（pgp）和ABCC（mrp）外排转运蛋白活性的大规模快速上调。 在大多数细胞中，多药转运蛋白插入膜是连续的，而在海胆中，这在受精后迅速发生。 因此，海胆为研究这一现象提供了一个强有力的模型。 在前两个目标中，候选人将通过转运蛋白向微绒毛尖端的移动来表征Sp-ABCB 1a（哺乳动物pgp的直系同源物）活性的受精后再分布（目标1）和Sp-ABCB 1a在活胚胎中定位的动力学（目标2）。 此后，他将这些发现扩展到小鼠模型，特别是对小鼠卵母细胞受精后pgp转运蛋白活性丧失的初步发现进行随访（目的3）。

DESCRIPTION (provided by applicant): The overall goal of this research is to understand the cell biological regulation of multidrug efflux transport activity during early embryo development. This application links two bodies of knowledge, the functional physiology of multidrug efflux transport, primarily studied in the context of cancer and epithelial transport, and the structural changes in cell surface and membrane organization, primarily studied in the context of cell and developmental biology. In this application, the candidate will characterize the relationship between cell surface changes that occur in early embryo development and the concomitant changes in the efflux transporter activity in two model organisms, the sea urchin and the mouse. The cell biology side is to understand how transport activity can be rapidly changed by cell stimuli and especially the relationship between structure (movement to microvilli) and function (prevention of entry of toxicants into the cell). The developmental biology side is to understand how the membrane of the unfertilized egg is altered from one specialized to fuse with the sperm to one that now protects and regulates subsequent development. The candidate's postdoctoral research has revealed massive and rapid up-regulation of ABCB (pgp) and ABCC (mrp) efflux transporter activity following fertilization of sea urchin eggs. In most cells insertion of multidrug transporters into the membrane is continuous, whereas in the sea urchin this occurs rapidly after fertilization. Thus, the sea urchin provides a powerful model for studying this phenomenon. In the first two aims, the candidate will characterize the post-fertilization redistribution of Sp-ABCB1a (an ortholog of mammalian pgp) activity by movement of the transporter to the tips of microvilli (Aim 1) and the dynamics of Sp-ABCB1a localization in living embryos (Aim 2). Thereafter, he will extend these findings to the mouse model, specifically following up on the preliminary finding of loss of pgp transporter activity after fertilization of mouse oocytes (Aim 3).