並列タイトル等酵母のフォスファチジルセリン非対称分布におけるリン脂質フリッペースの役割に関する研究
一般注記In eukaryotic cells, phosphatidylserine is predominantly located in the cytosolic leaflet of the plasma membrane; this asymmetry is generated by an unknown mechanism. In this study, I used the phosphatidylserine-specific probe mRFP-fused C2 domain of lactadherin (mRFP-Lact-C2) to investigate the possible involvement of type 4 P-type ATPases, also called phospholipid flippases, in the generation of this asymmetry in Saccharomyces cerevisiae. Phosphatidylserine was not found in the trans-Golgi Network in wild-type cells, but it became exposed when vesicle formation was compromised in the sec7 mutant, and it was also exposed on secretory vesicles, as reported previously. However, flippase mutations did not reduce the exposure of phosphatidylserine in either case, even at low levels that would only be detectable by quantitative analysis of mRFP-Lact-C2 fluorescence in isolated secretory vesicles. Furthermore, no reduction in the phosphatidylserine level was observed in a mutant with multiple flippase mutations. Because phosphatidylserine was not exposed in a mutant that accumulates endoplasmic reticulum (ER) or cis/medial-Golgi membranes, Golgi maturation seems to be a prerequisite for phosphatidylserine translocation. My results suggest that an unknown mechanism, possibly a protein with flippase-like activity, acts in conjunction with known flippases to regulate phosphatidylserine translocation.
(主査) 教授 田中 一馬, 教授 山下 正兼, 准教授 藤田 知道
生命科学院(生命科学専攻)
コレクション(個別)国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文
受理日(W3CDTF)2015-08-01T14:40:15+09:00
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