干细胞之家 - 中国干细胞行业门户第一站

 

 

搜索

点这里关注干细胞之家微信公众号

朗日生物希瑞干细胞
查看: 11893|回复: 89
go

Cdc14p turns MEN on and off

Rank: 7Rank: 7Rank: 7

积分
威望
0  
包包
3465  
发表于 2009-3-6 00:09 |显示全部帖子
The later stages of mitosis are complex. It is therefore inevitable that researchers working on the mitotic exit network (MEN) group of proteins would first keep things simple, and only later elaborate on their earlier, incomplete models. Two recent papers by Pereira et al. (page 367) and Stegmeier et al. (Stegmeier, F., R. Visintin, and A. Amon. 2002. Cell. 108:207–220) constitute an important part of this latter elaboration process.
2 e! e  Y1 b: i" ]" o
, P5 H& c0 f* H5 ~, G/ e( V% wBoth papers focus on the budding yeast Cdc14p phosphatase, which is released from the nucleolus so that it can kick the cell out of mitosis and into G1. (It does so by triggering the degradation of cyclin, and stabilizing the cyclin-dependent kinase inhibitor Sic1.) Previous work had stressed the action of the MEN, a network of regulatory proteins, in releasing and activating Cdc14p.8 }5 m; }$ t7 }8 m  z( d

3 R5 G6 b7 S7 }7 J0 k! Q$ eNow, Pereira et al. and Stegmeier et al. find that an early, partial release of Cdc14p from the nucleolus is independent of the MEN. Stegmeier et al. characterize a group of proteins, including the Polo kinase Cdc5 and separase Esp1p, that initiates this earlier release soon after anaphase onset. This may provide a link between chromosome segregation and mitotic exit, as both Cdc5 and Esp1 function in the degradation of the cohesin complex, the glue that holds sister chromatids together. Both research teams suggest that Cdc14p then helps to activate the MEN, thus initiating a positive feedback loop that liberates the remaining bulk of Cdc14p from the nucleolus.
1 X3 y( _6 `9 [) v6 N
4 I, B& \7 P2 R! V9 {) H4 qPereira et al. believe that this MEN-activating function of Cdc14p is independent of its phosphatase activity. They suggest, however, that the phosphatase activity of Cdc14p takes over later, when the cell is well on its way out of mitosis. At this time, Cdc14p may dephosphorylate and thus activate Bfa1p (part of an inhibitory, two- component GTPase-activating protein  complex), leading to inactivation of the MEN. These ideas are based on both in vitro and in vivo evidence, but will have to be confirmed with more direct biochemical readouts.(Early in anaphase, some Cdc14p (green) m)

Rank: 2

积分
162 
威望
162  
包包
1179  
发表于 2015-6-7 14:01 |显示全部帖子
观看中  

Rank: 2

积分
107 
威望
107  
包包
1344  
发表于 2015-7-10 16:10 |显示全部帖子
希瑞干细胞
看看..  
佰通生物

Rank: 2

积分
98 
威望
98  
包包
1212  
发表于 2015-7-13 22:08 |显示全部帖子
干细胞之家微信公众号
对不起,我走错地方了,呵呵  

Rank: 2

积分
88 
威望
88  
包包
1351  
发表于 2015-7-21 10:54 |显示全部帖子
偶真幸运哦...  

Rank: 2

积分
70 
威望
70  
包包
1265  
发表于 2015-8-22 16:52 |显示全部帖子
回复一下  

Rank: 2

积分
97 
威望
97  
包包
1194  
发表于 2015-9-19 19:56 |显示全部帖子
干细胞研究人员的天堂

Rank: 2

积分
70 
威望
70  
包包
1265  
发表于 2015-9-20 15:31 |显示全部帖子
dc-cik nk  

Rank: 2

积分
80 
威望
80  
包包
1174  
发表于 2015-9-28 22:18 |显示全部帖子
这个站不错!!  

Rank: 2

积分
101 
威望
101  
包包
1406  
发表于 2015-10-13 11:43 |显示全部帖子
看贴回复是好习惯  
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13001605号 )

GMT+8, 2018-10-20 09:23

Powered by Discuz! X1.5

© 2001-2010 Comsenz Inc.