干细胞之家 - 中国干细胞行业门户第一站

 

 

搜索
朗日生物

免疫细胞治疗专区

欢迎关注干细胞微信公众号

  
查看: 469486|回复: 242
go

An acid invasion [复制链接]

Rank: 7Rank: 7Rank: 7

积分
威望
0  
包包
3465  
楼主
发表于 2009-3-6 00:18 |只看该作者 |倒序浏览 |打印
Intracellular parasites must walk a fine line, invading and exploiting a host cell without killing it too quickly. On page 1029, Glomski et al. show how a single amino acid determines not only the pH optimum of a bacterial hemolysin, but also the virulence of an important pathogen. The data help explain how Listeria monocytogenes distinguishes between the membranes of acidic vesicles, which the bacterium must pierce to enter the cytosol, and the plasma membrane, which must remain intact while the parasite reproduces., Q6 `$ _$ Y1 z) }5 Z
  `2 G" F( ]5 H; |2 b
The activity of the L. monocytogenes pore-forming hemolysin listeriolysin O (LLO) is strongly induced by low pH. By amino acid substitution, the authors determined that changing a single residue largely relieves this pH dependence, but bacteria expressing the pH-independent form of the enzyme are 100-fold less virulent in mice. The virulence defect is not in cellular entry. The mutants escape from acidified phagosomes, grow in the cytosol, and spread from cell to cell. But bacteria expressing the mutant LLO permeabilize the host cell membrane prematurely. The authors propose that the acidic pH optimum of LLO is an adaptation to the parasitic lifestyle, allowing Listeria to penetrate acidic vesicles while leaving the plasma membrane intact.(A single residue determines acid sensiti)

Rank: 2

积分
122 
威望
122  
包包
1876  
沙发
发表于 2015-6-1 09:43 |只看该作者
神经干细胞

Rank: 2

积分
70 
威望
70  
包包
1809  
藤椅
发表于 2015-7-13 07:54 |只看该作者
心脏干细胞

Rank: 2

积分
72 
威望
72  
包包
1730  
板凳
发表于 2015-7-21 22:10 |只看该作者
干细胞之家微信公众号
真好。。。。。。。。。  

Rank: 2

积分
72 
威望
72  
包包
1859  
报纸
发表于 2015-8-14 18:54 |只看该作者
感觉好像在哪里看过了,汗~  

Rank: 2

积分
68 
威望
68  
包包
1752  
地板
发表于 2015-8-19 06:59 |只看该作者
拿把椅子看表演

Rank: 2

积分
77 
威望
77  
包包
1964  
7
发表于 2015-9-8 19:16 |只看该作者
孜孜不倦, 吾等楷模 …………  

Rank: 2

积分
97 
威望
97  
包包
1738  
8
发表于 2015-9-20 15:00 |只看该作者
希望大家帮我把这个帖发给你身边的人,谢谢!  

Rank: 2

积分
132 
威望
132  
包包
1727  
9
发表于 2015-10-3 19:02 |只看该作者
每天到干细胞之家看看成了必做的事情

Rank: 2

积分
107 
威望
107  
包包
1889  
10
发表于 2015-10-13 19:10 |只看该作者
支持一下吧  
‹ 上一主题|下一主题
你需要登录后才可以回帖 登录 | 注册
验证问答 换一个

Archiver|干细胞之家 ( 吉ICP备2021004615号-3 )

GMT+8, 2024-11-1 06:51

Powered by Discuz! X1.5

© 2001-2010 Comsenz Inc.