【经济学人】蛋白质图谱 | 2016.12.10 | 总第752期

ONE of the most important concepts in biology is compartmentalisation. Different organs do different jobs within bodies. Different tissues do different jobs within organs. Different cells within tissues, likewise. And within cells, different organelles—as subcellular components such as nuclei, mitochondria and Golgi bodies are known—are also specialised for particular functions. Each of these levels of organisation has, over the years, been catalogued in what have come to be known as atlases, beginning in 1543 with Andreas Vesalius’s “De Humani Corporis Fabrica” (On the Fabric of the Human Body), the founding text of modern anatomy.

区室化是生物学中最重要的概念之一。身体内的不同器官和器官内的各组织都各司其职。组织内的各细胞也是一样的。而在细胞内，不同的细胞器，如细胞核，线粒体和高尔基体（已知的亚细胞成分）都还有其特定的功能。期待您的翻译，您可以将翻译留言到文章底部，第二天会有详细解析哦。

• compartmentalisation n.区室化

• nuclei  ['njuːklɪaɪ] n.细胞核

• mitochondria [,maɪtəʊ'kɒndrɪə] n.线粒体

The latest level of detail is to look at different proteins within organelles. Proteins are the molecules that do most of the work within a cell. They range from things like actin and myosin, which collaborate to flex muscle cells—and thus the muscles of which those cells are part—to the enzymes of the Krebs cycle, which disassemble glucose to release the energy therein. The Cell Atlas, a database launched on December 4th at a meeting of the American Society of Cell Biology, records which proteins are found in which organelles. The result, like “De Humani Corporis Fabrica”, is both pleasing to the eye and important to the field. Proteins located together are likely to work together, so knowing a protein’s whereabouts within a cell will help researchers to determine its job.

最新的细节性研究可以具体到细胞器内不同的蛋白质的研究。蛋白质是细胞中执行大部分功能的分子。他们包括协作促使肌肉细胞收缩的肌动蛋白和肌球蛋白（因此这些细胞也是肌肉细胞的一部分），也包括分解葡萄糖释放能量的三羧酸循环酶。在12月4日细胞生物学美国学会年会上，设立了一个用于记载细胞器中蛋白质的细胞图谱数据库。这同《人体构造》一样既是个让人欣慰又是在生物学领域举足轻重的成果。这样一来相同位置的蛋白质可能协同工作，所以了解细胞内蛋白质位置有助于研究者确定细胞功效。

• collaborate [kə'læbəreɪt]  v.合作

• enzyme ['enzaɪm]  n.酶

• the Krebs cycle [krebz] 三羧酸循环

• disassemble [dɪsə'semb(ə)l] v.拆开，解开

• glucose ['gluːkəʊs; -z]：n.葡萄糖

The authors of the Cell Atlas, led by Mathias Uhlen of the Royal Institute of Technology, in Stockholm, have pinned 12,051 proteins down in this way using immunofluorescence. This technique employs specially created antibodies (protein molecules, produced by immune-system cells, that bind specifically to a particular target protein) to hunt down that target within a cell. The antibodies themselves have fluorescent tags attached to them, so that they will glow when exposed to ultraviolet light. 

由斯德哥尔摩皇家理工学院Mathias Uhlen带领的细胞图谱作者们，用荧光免疫检验法确定了12051个蛋白质的位置。这种技术采用专有抗体（免疫系统细胞生成的绑定特定靶蛋白的蛋白质分子）在细胞内追踪目标。因为抗体本身带有荧光标记，因此紫外线照射时会发光。

• immunofluorescence [,ɪmjʊnəʊ,flʊə'res(ə)ns]n.[免疫]荧光免疫检验法

• ultraviolet light  [ʌltrə'vaɪələt] n.紫外线

By applying these tagged antibodies to cells from 22 human-cell lines derived from a range of original tissues, the atlas’s authors gave themselves the best possible chance of detecting a particular protein in cells of at least one line. That done, each sample was examined microscopically to determine which of the 13 generally recognised organelles each protein appeared in. This, being quite a task (and not one easily delegated to automatic optical-recognition systems), was carried out in part by a bunch of 120,000 enthusiastic amateurs.

通过将已标记抗体应用于来自一系列原始组织的22个人体细胞株的细胞之内，图谱作者得到了一个至少一次能在一个细胞株中测定某一特定蛋白质的绝佳机会。随后他们会用显微镜对每个样品检查，以便确定了已知的13个细胞器中每个蛋白质的位置。这是一个相当繁琐的任务（不是一个仅靠自动光学识别系统的就能完成的任务），一部分由120000名热情的业余爱好者完成。

• derive from [dɪ'raɪv] v.源于，来自

• delegate [ˈdɛlɪˌɡeɪt] n.代表

The example in the picture is of the distribution of a protein (tagged green) called ZNF554. This belongs to a group, the zinc-finger transcription factors, whose job is to activate and regulate genes. As the picture shows, ZNF554 is restricted to the cell’s nucleus. Within that nucleus there are several places which glow particularly brightly, and where it is therefore particularly abundant. These are the nucleoli—zones where genes are especially active. (The red areas are the cell’s microtubules. These act as its skeleton and are tagged in all Cell Atlas pictures, in order to outline a cell’s limits.)

图中的例子是名为ZNF554的蛋白质的分布图。这种蛋白质属于锌指转录因子。锌指转录因子的功能是激活和调节基因。如图所示，ZNF554蛋白质只存在于细胞核内。在细胞核内有几个地方发出特别亮，因此这些地方的ZNF554蛋白质特别多。这些地方是细胞核仁（基因异常活跃的区域）。（红色的区域是细胞的微管。它们相当于细胞的骨架。细胞图谱把它们全部标记出来了以便勾勒出细胞的边界。）

• the zinc-finger transcription factors

•     [zɪŋk] ['fɪŋgə] [træn'skrɪpʃ(ə)n]['fæktəz]

•     n.锌指转录因子

• microtubules [maɪkrə(ʊ)'tjuːbjuːl]：n.微管

• nucleoli [njʊ'kliəlaɪ]：n.核仁

What fraction of human proteins the Cell Atlas currently covers is open to debate. The number of protein-coding genes in the human genome is currently reckoned at 19,628. Some genes, however, can yield more than one protein—either because they may be read in more than one way, or because their messages to the protein-manufacturing parts of a cell may end up edited in different ways. This means the actual number of proteins that can exist from time to time in the body exceeds the number of genes, probably by at least 50%. The Cell Atlas, then, is by no means the last word on the matter of where proteins are found. But it is a good start.

目前细胞图谱收录这部分人体蛋白质饱受大家的争议。目前认为人类基因组中蛋白质编码基因的数量大约有19628种。然而一些基因不止能产生一种蛋白质（或许因为解读它们的方法不止一种，又或是因为它们自身给蛋白质生成部分发出的指令的编写方式不同）。这意味着有时人体内蛋白质的实际数目会超过基因数目，可能至少超过基因数量的50％。因此细胞图谱绝不是探讨蛋白质位置问题的最终答案。而是一个好的开端。

• Protein-manufacturing

• ['prəʊtiːn][,mænjʊ'fæktʃərɪŋ]

• adj.制造蛋白质的        

• From time to time：adv.不时，偶尔，

•  Exceeds [ɪk'siːd]：v.超过; 超越

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