人类首次在健康细胞中发现四链 DNA

2020年8月13日09:45:38人类首次在健康细胞中发现四链 DNA已关闭评论 421 3025字阅读10分5秒
摘要

世界上最著名的分子——DNA 双螺旋结构——有时会再次折叠起来。研究人员现在首次在健康的人类细胞中发现了这种四链结构。

LIFE  20 July 2020

By Rowan Hooper


The double helix gets an upgrade 双螺旋:发现DNA结构的故事得到了升级

Ella Maru Studio

The world's most famous molecule–the DNA double helix–sometimes doubles up again.Researchers have now found this quadruple-stranded form in healthy human cells for the first time.

世界上最著名的分子——DNA 双螺旋结构——有时会再次折叠起来。研究人员现在首次在健康的人类细胞中发现了这种四链结构。

Four-stranded DNA has been seen before in some cancer cells and in lab-based chemistry experiments,but this is the first time the molecule has been visualised in healthy,living human cells,as a stable structure created by normal cellular processes.

以前在一些癌细胞和实验室化学实验中已经发现了四链 DNA,但这是第一次在健康、活着的人类细胞中观察到这种分子,它是由正常细胞过程产生的一种稳定结构。

"We've undoubtedly demonstrated that the quadruple-strand DNA forms in living cells,"says Marco Di Antonio at Imperial College London."This forces us to rethink the biology of DNA."

"毫无疑问,我们已经证明了四链 DNA 在活细胞中形成,"伦敦帝国理工学院的马可··安东尼奥说。"这迫使我们重新思考 DNA 的生物学。"

The DNA molecule is made up of four nucleobases–adenine,cytosine,guanine and thymine–and can configure itself in a number of ways.It creates a four-stranded structure when four guanine bases form a square–guanine is the only base able to bond with itself.

DNA 分子由腺嘌呤、胞嘧啶、鸟嘌呤和胸腺嘧啶四种碱基组成,可以通过多种方式进行配置。当四个鸟嘌呤碱基形成一个正方形鸟嘌呤时,它就形成了一个四链结构。正方形鸟嘌呤是唯一能与自身结合的碱基。

Di Antonio,who conducted the work while at the University of Cambridge,and his colleagues were able to visualise the quadruple form within human tissue by attaching a new kind of fluorescent marker to DNA in living cells.He says the discovery may improve our understanding of how the genetic material divulges its information.

在剑桥大学进行这项研究的迪·安东尼奥和他的同事们通过在活细胞中的 DNA 上附加一种新的荧光标记,可以观察到人体组织中的四重形式。他说,这一发现可能会提高我们对遗传物质如何泄露其信息的理解。

"We know exactly what DNA does,"says Di Antonio,"but how does the cell know where to express genes and how much protein to make?"The researchers speculate that the quadruplex structure forms to hold the molecule open and facilitate the reading of the genetic code and thus the production of proteins.It may also influence the amount of each protein that is made.

"我们确切地知道 DNA 是做什么的,"安东尼奥说,"但是细胞是如何知道在哪里表达基因以及制造多少蛋白质的呢?"研究人员推测,这种四链结构的形成是为了保持分子的开放性,并促进对遗传密码的解读,从而产生蛋白质。它也可能影响每种蛋白质的产量。

Usually,this function is performed by epigenetic markers–chemical tags on DNA that increase or decrease the activity of genes–and it seems that the quadruplex form of DNA has a similar role."There is a sort of crosstalk between the formation of quadruplex DNA and epigenetic markers,"says Di Antonio."The quadruplex form is an epigenetic mark in its own right."

通常,这种功能是由表观遗传标记(DNA 上的化学标记,增加或减少基因的活性)完成的,看起来,四链形式的 DNA 也有类似的作用。"四链 DNA 的形成与表观遗传标记之间存在一种相互干扰,"安东尼奥说。四联体形式本身就是一种表观遗传标记

Zoë Waller at the University of East Anglia,UK,says the work adds to the evidence that the quadruplex structures form part of normal DNA regulation and function,and that our view of the DNA double helix may be out of date."We presume that this is the normal,native state of DNA,but this work is another exceptional example of mounting evidence that DNA is not a fixed structure or shape,"she says.

英国东英吉利亚大学的 zoë Waller 说,这项工作进一步证明了四链结构是正常 DNA 调节和功能的一部分,而且我们对 DNA 双螺旋结构的认识可能已经过时了。她说:"我们认为这是 DNA 的正常的自然状态,但是这项工作是另一个例外,证明了 DNA 不是一个固定的结构或形状。"

Journal reference:Nature Chemistry,DOI:10.1038/s41557-020-0506-4

参考文献:Nature ChemistryDOI:10.1038/s41557-020-0506-4

来源:https://www.newscientist.com/article/2249390-quadruple-stranded-dna-seen-in-healthy-human-cells-for-the-first-time/

  • 本文由 发表于 2020年8月13日09:45:38
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