Mechanism of Host Cell Death Induced by Infection of Escherichia Coli with the c2 Clear-Plaque Mutant of Phage f1

從野生型線狀噬菌體f1混濁狀溶斑(turbid plaque)挑到一個澄清狀溶菌斑(clear plaque)突變株c2，此突變株c2感染寄主後會造成寄主死亡，本研究觀察c2造成寄主死亡之機轉，在感染30分鐘後，寄主細胞膜電位大量喪失，而4小時後，寄主細胞內含物有大量外漏情形，且經穿透式電顯可觀察到在c2感染早期，寄主細胞內有大量膜頭顆粒累積，更進一步分析c2感染後寄主細胞膜蛋白組成之改變，發現在c2感染2小時後，許多寄主細胞膜外膜蛋白即顯著減少，且噬菌體外殼基因Ⅷ蛋白質與單股DNA結合基因V蛋白質，大量累積在細胞膜內膜，由以上結果顯示，此澄清狀溶菌斑突變株c2感染寄主後，會造成寄主細胞膜之傷害而導致寄主死亡。

關鍵字

寄主細胞死亡；澄清狀溶菌斑；大腸桿菌；線狀噬菌體f1

並列摘要

The c2 clear-plaque mutant arose spontaneously from the turbid plaque-inducing wild-type strain of bacteriophage f1. The mechanism of host cell death induced by infection of Escherichia coil with c2 has now been investigated. A marked decrease in cell membrane potential was apparent as early as 30mm after infection with c2, and leakage of cell contents was apparent after 4h. Transmission electron microscopy also revealed the accumulation of granular membrane-like structures within cells at early stages of c2 infection. Electrophoretic analysis showed that the abundance of several bacterial outer membrane proteins was markedly reduced 2h after infection with c2. Furthermore, substantial amounts of the phage coat protein (gpⅧ) and single-stranded DNA-binding protein (gpV) were apparent in the inner membrane of c2-infected cells 2h after infection. These data support the hypothesis that the death of c2-infected cells results from phage-induced damage to the bacterial cell membrane.

並列關鍵字

Cell death ； Clear plaque ； Escherichia coli ； Filamentous phage f1

國際替代計量

Mechanism of Host Cell Death Induced by Infection of Escherichia Coli with the c2 Clear-Plaque Mutant of Phage f1

全文下載

主題瀏覽