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One more C means no hearing [復制鏈接]

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樓主
發表于 2009-3-6 08:41 |只看該作者 |倒序瀏覽 |打印
MAMMANO/MACMILLAN0 ]* t4 _% V3 h0 {4 P
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A miniscule change in a pore protein can mean the difference between hearing and deafness, say Martina Beltramello, Valeria Piazza, Fabio Mammano (Venetian Institute of Molecular Medicine, Padua, Italy), and colleagues. They have characterized a mutant connexin from the inner ear that allows the passage of ions and a dye, but not of the intracellular messenger inositol 1,4,5-trisphosphate (IP3). The result is a failure in hearing.The connexin is expressed in supporting cells in the organ of Corti (http://www.vimm.it/cochlea). These cells are thought to ferry K  away from sensory cells, thus preventing opening of channels in these cells that would admit toxic levels of Ca2 .
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$ ]& {3 s9 i, \# |$ a, cMost connexin mutations associated with deafness yield missorted or nonfunctional channel proteins. The Italian group focused on the V84L mutant, which is correctly sorted and, as they show, forms channels with normal unitary conductance and open channel probabilities. Ions and the higher molecular weight dye Lucifer yellow can pass through these channels.
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3 v4 g/ g3 d3 h0 sBut IP3 introduced into cells expressing V84L mutant connexins did not, as in wild type, generate Ca2  waves in adjacent cells. Failure to spread this message may be the basis for a failure in K  scavenging and thus sensory cell death.
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Thus the addition of a single CH2 unit can determine the difference between conductance and nonconductance of IP3. The detailed structure of the relevant connexin is not yet known, but the minimal structural difference may be amplified if the residue in question pokes into the channel that is formed by 6 connexin subunits.! ]# {2 h0 B& T, q$ `

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Beltramello, M., et al. 2004. Nat. Cell Biol. doi:10.1038/ncb1205.(IP3 spreads to elicit Ca2  peaks via wil)

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沙發
發表于 2015-6-1 13:00 |只看該作者
造血干細胞

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藤椅
發表于 2015-6-1 14:43 |只看該作者
幫你項項吧  

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板凳
發表于 2015-6-1 15:17 |只看該作者
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天啊. 很好的資源

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報紙
發表于 2015-6-7 21:01 |只看該作者
慢慢來,呵呵  

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地板
發表于 2015-6-14 03:57 |只看該作者
呵呵 都沒人想我~~  

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發表于 2015-6-25 08:23 |只看該作者
不看白不看,看也不白看  

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發表于 2015-7-18 15:34 |只看該作者
加油啊!偶一定會追隨你左右,偶堅定此貼必然會起到拋磚引玉的作用~  

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發表于 2015-9-5 19:21 |只看該作者
干細胞研究人員的天堂

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發表于 2015-9-10 13:07 |只看該作者
干細胞存儲  
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