首页 | 本学科首页   官方微博 | 高级检索  
   检索      


The Cellular Concentration of the Yeast Ure2p Prion Protein Affects Its Propagation as a Prion
Authors:Myriam Crapeau  Christelle Marchal  Christophe Cullin  and Laurent Maillet
Abstract:The URE3] yeast prion is a self-propagating inactive form of the Ure2p protein. We show here that Ure2p from the species Saccharomyces paradoxus (Ure2pSp) can be efficiently converted into a prion form and propagate URE3] when expressed in Saccharomyces cerevisiae at physiological level. We found however that Ure2pSp overexpression prevents efficient prion propagation. We have compared the aggregation rate and propagon numbers of Ure2pSp and of S. cerevisiae Ure2p (Ure2pSc) in URE3] cells both at different expression levels. Overexpression of both Ure2p orthologues accelerates formation of large aggregates but Ure2pSp aggregates faster than Ure2pSc. Although the yeast cells that contain these large Ure2p aggregates do not transmit URE3] to daughter cells, the corresponding crude extract retains the ability to induce URE3] in wild-type ure3-0] cells. At low expression level, propagon numbers are higher with Ure2pSc than with Ure2pSp. Overexpression of Ure2p decreases the number of URE3] propagons with Ure2pSc. Together, our results demonstrate that the concentration of a prion protein is a key factor for prion propagation. We propose a model to explain how prion protein overexpression can produce a detrimental effect on prion propagation and why Ure2pSp might be more sensitive to such effects than Ure2pSc.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号