由德州農(nóng)工大學(xué)和辛辛那提大學(xué)的科學(xué)家組成的研究小組發(fā)現(xiàn)，在DNA結(jié)構(gòu)和與端粒的關(guān)系,，以及它們?nèi)绾斡绊懠?xì)胞老化和癌癥方面,，一種常見的雜草-擬南芥和人類的癌細(xì)胞能夠提供一些非常特殊的信息。
在這項(xiàng)研究中,，小組人員檢測(cè)了擬南芥（Arabidopsis）的端粒,，發(fā)現(xiàn)了一套新的重要的端粒蛋白,。然后在人類研究中，他們發(fā)現(xiàn)該蛋白可能有助于理解人類的癌癥和細(xì)胞老化,。該研究結(jié)果發(fā)布在近期的Molecular Cell上,。
端粒位于每個(gè)染色體的末端，由DNA和蛋白質(zhì)組成,。其主要的功能是保護(hù)染色體的末端,，它們同樣在細(xì)胞分裂中具有重要作用。研究人員相信在細(xì)胞壽命方面端粒也承擔(dān)了重要的角色,。
研究人員發(fā)現(xiàn)移除植物的端粒蛋白會(huì)導(dǎo)致染色體末端與末端相連,，對(duì)植物生長(zhǎng)產(chǎn)生重要影響。此外,，在移除人類癌細(xì)胞的一個(gè)蛋白后,，他們發(fā)現(xiàn)這引起了廣泛的DNA損壞，導(dǎo)致一些端粒的完全丟失,。研究人員介紹說(shuō),，端粒在保護(hù)染色體方面具有重要作用，其帽子能夠阻止染色體并合,。同樣端粒的長(zhǎng)度也決定了細(xì)胞分裂的次數(shù),。
然而，科學(xué)家還不能完全理解端粒的帽子結(jié)構(gòu)如何阻止染色體連接或調(diào)控端粒長(zhǎng)度,。這是一個(gè)重要的問題,，因?yàn)槎肆Ｈ绻鰡栴}會(huì)導(dǎo)致疾病發(fā)生，比如癌癥,，過(guò)早老化,，再生障礙性貧血，肺纖維化等,。這個(gè)新發(fā)現(xiàn)的蛋白復(fù)合物能保護(hù)端粒的帽子結(jié)構(gòu),，或能為人類疾病的相關(guān)研究開辟新的道路。（生物谷Bioon.com）
近期熱點(diǎn)：
端粒及端粒酶研究獲得09年諾貝爾生理學(xué)或醫(yī)學(xué)獎(jiǎng)
童坦君院士,、譚錚研究員：端粒研究方興未艾
端粒詳解：
端粒和端粒酶的發(fā)現(xiàn)歷程
周金秋研究員：端粒——穩(wěn)定線性染色體的末端結(jié)構(gòu)
生物谷推薦原始出處：
Molecular Cell, 23 October 2009 doi:10.1016/j.molcel.2009.09.017
Conserved Telomere Maintenance Component 1 Interacts with STN1 and Maintains Chromosome Ends in Higher Eukaryotes
Yulia V. Surovtseva1, 3, Dmitri Churikov2, Kara A. Boltz1, Xiangyu Song1, Jonathan C. Lamb1, Ross Warrington1, 4, Katherine Leehy1, Michelle Heacock1, 5, Carolyn M. Price2, , and Dorothy E. Shippen1, ,
1 Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX 77843-2128, USA
2 Department of Cancer and Cell Biology, University of Cincinnati, Cincinnati, OH 45267, USA
3 Present address: Department of Pathology, Yale University School of Medicine, P.O. Box 208023, New Haven, CT 06520-8023, USA
4 Present address: Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center Dallas, TX 75390, USA
5 Present address: Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
Orthologs of the yeast telomere protein Stn1 are present in plants, but other components of the Cdc13/Stn1/Ten1 (CST) complex have only been found in fungi. Here we report the identification of conserved telomere maintenance component 1 (CTC1) in plants and vertebrates. CTC1 encodes an ～140 kDa telomere-associated protein predicted to contain multiple OB-fold domains. Arabidopsis mutants null for CTC1 display a severe telomere deprotection phenotype accompanied by a rapid onset of developmental defects and sterility. Telomeric and subtelomeric tracts are dramatically eroded, and chromosome ends exhibit increased G overhangs, recombination, and end-to-end fusions. AtCTC1 both physically and genetically interacts with AtSTN1. Depletion of human CTC1 by RNAi triggers a DNA damage response, chromatin bridges, increased G overhangs, and sporadic telomere loss. These data indicate that CTC1 participates in telomere maintenance in diverse species and that a CST-like complex is required for telomere integrity in multicellular organisms.
