干細胞之家 - 中國干細胞行業門戶第一站

 

 

搜索
朗日生物希瑞干細胞
查看: 29261|回復: 117
go

An exit exchanger [復制鏈接]

Rank: 7Rank: 7Rank: 7

積分
威望
0  
包包
3465  
樓主
發表于 2009-3-6 08:22 |只看該作者 |倒序瀏覽 |打印
The protozoan parasite Toxoplasma gondii heads out of its host cell when Ca2  levels peak in its cytoplasm. Now, Arrizabalaga et al. (page 653) find that proper regulation of these Ca2  levels, and thus of Toxoplasma exit, requires a Na /H  exchanger (NHE), suggesting a link between proton and Ca2  regulation.6 y$ h. A9 j& L3 e# O
* K9 ]/ w0 O5 }9 W% l) U* u( x
The increase in Ca2  levels, which can be induced artificially with an ionophore, triggers a series of morphological changes that primes Toxoplasma for both exit and a speedy entrance into a neighboring cell. Death can ensue, however, if the ionophore sticks around while there is no target cell for the parasite to enter; presumably the overstimulated Toxoplasma cannot sustain itself in an activated state.
- j0 R5 ]  d- n6 x* E5 Q" K
0 K& g  L( F+ N* {0 ZThe authors used this death assay to isolate a mutant defective in activation. One mutant with a disruption in a sodium/hydrogen exchanger (NHE) showed both delayed exit and reduced Toxoplasma cell death after sustained ionophore exposure. Toxoplasma lacking this plasma membrane pump also had normal internal pH, but their proton efflux was no longer prevented with an NHE inhibitor.% S% {1 r/ S8 q# k# H" `8 z
  z- a4 H  o8 b- i
Resting Ca2  levels were higher in mutant parasites. This would make it harder to detect any exit signal that increased these Ca2  levels even further, perhaps explaining why these mutants are slow to exit. The increase in resting Ca2  levels may come about if a Ca2  exporter (Ca2  out/H  in) relies on prior action of the NHE (H  out/Na  in). Such a hypothetical linkage may be part of regulating Toxoplasma mobility or simply an intersection between the exit system and Toxoplasma's normal ion homeostasis.(Toxoplasma need a plasma membrane ion ex)

Rank: 2

積分
75 
威望
75  
包包
1833  
沙發
發表于 2015-7-18 16:10 |只看該作者
慢慢來,呵呵  

Rank: 2

積分
98 
威望
98  
包包
1926  
藤椅
發表于 2015-7-28 09:10 |只看該作者
希瑞干細胞
每天早上起床都要看一遍“福布斯”富翁排行榜,如果上面沒有我的名字,我就去上班……  

Rank: 2

積分
73 
威望
73  
包包
1549  
板凳
發表于 2015-8-7 16:32 |只看該作者
干細胞之家微信公眾號
(*^__^*) 嘻嘻……   

Rank: 2

積分
118 
威望
118  
包包
1484  
報紙
發表于 2015-9-12 02:01 |只看該作者
誰都不容易啊 ~~  

Rank: 2

積分
136 
威望
136  
包包
1592  
地板
發表于 2015-9-17 17:27 |只看該作者
文筆流暢,修辭得體,深得魏晉諸朝遺風,更將唐風宋骨發揚得入木三分,能在有生之年看見樓主的這個帖子。實在是我三生之幸啊。  

Rank: 2

積分
77 
威望
77  
包包
1445  
7
發表于 2015-9-30 01:56 |只看該作者
拿分走人呵呵,樓下繼續!

Rank: 2

積分
98 
威望
98  
包包
1926  
8
發表于 2015-10-15 12:43 |只看該作者
嚴重支持!

Rank: 2

積分
162 
威望
162  
包包
1461  
9
發表于 2015-11-6 18:49 |只看該作者
有空一起交流一下  

Rank: 2

積分
132 
威望
132  
包包
1442  
10
發表于 2015-11-13 10:43 |只看該作者
強人,佩服死了。呵呵,不錯啊  
‹ 上一主題|下一主題
你需要登錄后才可以回帖 登錄 | 注冊
驗證問答 換一個

Archiver|干細胞之家 ( 吉ICP備13001605號 )

GMT+8, 2019-7-7 16:09

Powered by Discuz! X1.5

© 2001-2010 Comsenz Inc.

英格兰球衣号码2019