干细胞之家 - 中国干细胞行业门户第一站

 

 

搜索
朗日生物

干细胞技术讨论区

干细胞临床应用技术交流

免疫细胞治疗专区

欢迎关注干细胞微信公众号

查看: 69820|回复: 132
go

Microsomes are the in vitro ER

Rank: 7Rank: 7Rank: 7

积分
威望
0  
包包
3465  
发表于 2009-3-6 08:41 |显示全部帖子
PALADE
, E' q& K  q/ @5 g/ ~  c8 E. ^- t4 P# h* ~! d4 O  [
The abundance of electron microscope (EM) images in the 1940s and 1950s brought a new problem: nomenclature. What to call all those black smudges? As recalled by Palade (1956), "it appears that, at that time, our group was not yet engaged in large scale production of new cytological terms with a heavy Latin flavor, and was still proceeding with cautious restraint in matters of nomenclature." But there were plenty to take Palade's place.
# L, m7 X0 i: }/ }, Y6 X
; T6 W; u* E; a0 APerhaps the first connection between two parts of this nomenclature came with a paper by Palade and Siekevitz (1956a). They united the fields of microscopy and fractionation to conclude that Albert Claude's biochemical fraction called microsomes (Claude, 1943) were none other than the in vitro version of the endoplasmic reticulum (ER)〞a cytological feature first noted by Keith Porter (Porter, 1953).( W3 I1 o- l/ ]4 o* ^

8 r' B3 _: g% A# _! vClaude had stumbled upon microsomes when he was hunting for Rous sarcoma virus. His RNA-containing fraction was a promising place to find an RNA virus, but unfortunately an identical RNA-containing fraction could be isolated from uninfected cells. Numerous investigators later suggested that microsome fractions were linked to protein synthesis, as they were the first fractions to incorporate radioactive amino acids.! m( Q2 |+ r6 |; s" S
/ N9 O: N% y9 z
Now, the problem was to find the in vivo correlate of microsomes. Although microsomes from rat liver cells were more fragmented than the original ER, the general structure of the membranous compartment stayed consistent throughout the fractionation. More tellingly, bound "dense particles" (now known as ribosomes) were a characteristic mark of both the in vivo and in vitro structures. The microsomes "could only have come from a fragmentation of the ER," says Siekevitz. "It was the only thing in the cell that they resembled." Detergent treatment then showed that the ribosomes were the RNA-rich components of the ER.# o* `+ `& Q4 O. Q

- ~# U) ?1 O$ J* o+ D& l1 V- sThese findings were reproduced in pancreatic cells by Palade and Siekevitz (1956b), who made special note of "the frequent association of the small particles in chains and relatively large, more or less orderly organized masses." At least some of these patterns, and the "parallel double rows, loops, spirals, circles, and rosettes" noted in the original description of ribosomes by Palade (1955) were probably polysomes〞a structure whose existence was not fully proven for another 6 years (Warner et al., 1962). During that period Palade had continued success in combining EM and fractionation, which contributed in no small part to his receiving the 1974 Nobel Prize in Physiology or Medicine along with Claude and Christian de Duve.. `* i( I) |2 H! a0 M& x

* ?$ @( s. s! }( _) H3 g/ {Claude, A. 1943. Science. 97:451–456.
9 b+ }" m) ]1 Y1 o7 P, _+ y: L; z! X4 k/ ^0 i4 Z, u! G9 M
Palade, G.F. 1955. J. Biophys. Biochem. Cytol. 1:59–68.
& _. R: e5 t* e) }! Z: g$ @7 W$ c" C; L& w
Palade, G.F. 1956. J. Biophys. Biochem. Cytol. 2:85–97.$ T0 `4 C  f) c6 @3 \) M; E# h

) J1 R0 I; H) H3 |8 T7 w# G5 hPalade, G.F., and P. Siekevitz. 1956a. J. Biophys. Biochem. Cytol. 2:171–200.
* R# L1 k3 g  o7 Q. t
, u0 S9 C; k! Y; _9 L! YPalade, G.F., and P. Siekevitz. 1956b. J. Biophys. Biochem. Cytol. 2:671–690.& f  ^( h/ O) S+ L. d6 _9 P( r5 U

1 w: b  k# ?) p: C' }1 ]Porter, K.R. 1953. J. Exp. Med. 97:727–750.3 |: z( |- C2 A4 n- |* s( a+ U. |! ^
, s6 }) g% T; F+ l, e
Warner, J.R., et al. 1962. Science. 138:1399–1403.(Microsomes (here) and ER look similar, a)

Rank: 2

积分
132 
威望
132  
包包
1577  
发表于 2015-5-25 11:18 |显示全部帖子
哈哈,看的人少,回一下  

Rank: 2

积分
70 
威望
70  
包包
1659  
发表于 2015-6-4 20:10 |显示全部帖子
快毕业了 希望有个好工作 干细胞还是不错的方向

Rank: 2

积分
64 
威望
64  
包包
1631  
发表于 2015-6-26 18:27 |显示全部帖子
干细胞之家微信公众号
不早了 各位晚安~~~~  

Rank: 2

积分
72 
威望
72  
包包
1579  
发表于 2015-7-8 09:54 |显示全部帖子
我的妈呀,爱死你了  

Rank: 2

积分
97 
威望
97  
包包
1588  
发表于 2015-7-13 15:43 |显示全部帖子
偶真幸运哦...  

Rank: 2

积分
72 
威望
72  
包包
1792  
发表于 2015-7-23 22:31 |显示全部帖子
真的有么  

Rank: 2

积分
122 
威望
122  
包包
1726  
发表于 2015-7-25 20:27 |显示全部帖子
鉴定完毕.!  

Rank: 2

积分
70 
威望
70  
包包
1659  
发表于 2015-9-4 18:53 |显示全部帖子
初来乍到,请多多关照。。。  

Rank: 2

积分
72 
威望
72  
包包
1792  
发表于 2015-9-15 13:54 |显示全部帖子
造血干细胞
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, 2019-11-19 12:58

Powered by Discuz! X1.5

© 2001-2010 Comsenz Inc.