Ganguly Sourav, Singh Pushpendra, Manoharlal Raman, Prasad Rajendra, Chattopadhyay Amitabha
Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, Andhra Pradesh, India.
Biochem Biophys Res Commun. 2009 Oct 2;387(4):661-5. doi: 10.1016/j.bbrc.2009.07.054. Epub 2009 Jul 16.
Lateral diffusion of lipids and proteins in yeast plasma membranes has been reported to be anomalously slow, and implicated as a possible reason for polarization in yeast. In order to gain insight into the observed slow diffusion in yeast membranes, we explored lateral diffusion of two proteins of different origin. We compared lateral dynamics of the Candida drug resistance protein-1 (Cdr1p), and the human serotonin(1A) receptor (5-HT(1A)R) by fluorescence recovery after photobleaching (FRAP). Our results show that while Cdr1p-GFP displays slow diffusion, the diffusion of 5-HT(1A)R-EYFP is significantly faster. Interestingly, upon ergosterol depletion, the mobility of Cdr1p-GFP did not exhibit appreciable change, while 5-HT(1A)R-EYFP mobility showed an increase. On the other hand, upon actin cytoskeleton destabilization, the mobile fraction of 5-HT(1A)R-EYFP showed considerable increase, while the mobility of Cdr1p-GFP was not altered. Our results represent the first report on the dynamics of the important drug resistance protein Cdr1p and provide novel insight on diffusion of membrane proteins in yeast membranes.
据报道，酵母质膜中脂质和蛋白质的横向扩散异常缓慢，这被认为是酵母极化的一个可能原因。为了深入了解在酵母膜中观察到的缓慢扩散现象，我们研究了两种不同来源蛋白质的横向扩散。我们通过光漂白后荧光恢复（FRAP）比较了白色念珠菌耐药蛋白-1（Cdr1p）和人5-羟色胺（1A）受体（5-HT(1A)R）的横向动力学。我们的结果表明，虽然Cdr1p-GFP表现出缓慢扩散，但5-HT(1A)R-EYFP的扩散明显更快。有趣的是，在麦角固醇耗尽时，Cdr1p-GFP 的流动性没有明显变化，而5-HT(1A)R-EYFP的流动性增加。另一方面，在肌动蛋白细胞骨架不稳定时，5-HT(1A)R-EYFP的可移动部分显著增加，而Cdr1p-GFP的流动性没有改变。我们的结果首次报道了重要耐药蛋白Cdr1p的动力学，并为酵母膜中膜蛋白的扩散提供了新的见解。
