生物通報(bào)道  在多細(xì)胞生物的細(xì)胞社會中，細(xì)胞間或細(xì)胞內(nèi)通過高度和地發(fā)送與接收信息，并通過放大引起快速的細(xì)胞生理反應(yīng)，或者引起基因活動，引發(fā)一系列的細(xì)胞生理活動來協(xié)調(diào)各組織活動，使之成為生命的統(tǒng)一整體對多變的外界環(huán)境做出綜合反應(yīng)，這一機(jī)制就被稱作細(xì)胞通訊（Cell communication）。在細(xì)胞通訊過程中，靶細(xì)胞通過細(xì)胞表面受體接收到來自信號傳導(dǎo)細(xì)胞發(fā)送的分子，進(jìn)而觸發(fā)靶細(xì)胞應(yīng)答。生物通
近日來自密西根大學(xué)醫(yī)學(xué)院和麻省理工學(xué)院等機(jī)構(gòu)的研究人員在新研究發(fā)現(xiàn)細(xì)胞間的通訊并非只是一個單向的信號傳導(dǎo)過程，靶細(xì)胞可反過來發(fā)出接收信息，告訴對方自己所需的信號量。這一發(fā)現(xiàn)或可幫助研究人員找到調(diào)控細(xì)胞信號傳導(dǎo)的新途徑，對推動合成生物學(xué)和癌癥轉(zhuǎn)移研究均具有重要的意義。相關(guān)研究成果發(fā)表在*學(xué)術(shù)期刊《科學(xué)》（Science）旗下子刊《科學(xué)信號》（Science Signaling）雜志上。
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領(lǐng)導(dǎo)這一研究的是麻省理工學(xué)院生物醫(yī)學(xué)工程學(xué)系的副教授Domitilla Del Vecchio。Del Vecchio和他的研究小組早在三年前便提出細(xì)胞內(nèi)的信號系統(tǒng)有可能檢測到并對鄰近的受體作出信號反應(yīng)。新研究*次獲得了直接的實(shí)驗(yàn)數(shù)據(jù)支持了這一假說。
Del Vecchio稱這一效應(yīng)就像電氣或水壓系統(tǒng)中的壓力閥。例如當(dāng)你在沖洗馬桶時，鄰近水的水壓可能會隨之下降控制水流進(jìn)入，使水箱中的水量及時得以補(bǔ)充。相類似的是，細(xì)胞也會以發(fā)送信號分子的方式對一些可變的刺激作出回應(yīng)，通過調(diào)整下游效應(yīng)器——細(xì)胞內(nèi)受體接受這一信號就可使細(xì)胞的響應(yīng)時間發(fā)生改變。
普林斯頓大學(xué)化學(xué)和生物工程學(xué)系教授Stanislav Shvartsman （未參與這一研究）對此評論說：“信號級聯(lián)反應(yīng)通常被描述為是單向的。Del Vecchio和他的同事早前的一些研究曾引發(fā)了一些爭議。新研究借助于精巧設(shè)計(jì)、開展的實(shí)驗(yàn)為他們早期的理論提供了令人信服的數(shù)據(jù)，并深刻地改變了我們對于細(xì)胞內(nèi)信號傳導(dǎo)的理解。”生物通
這一研究發(fā)現(xiàn)或有可能幫助研究人員找到控制某些疾病進(jìn)程的新途徑。“近期很多的研究論文都在討論異常信號對癌癥形成的影響，”Vecchio說：“這一發(fā)現(xiàn)提供了一個細(xì)胞選擇信號接受的重要范例，或?qū)⒋偈拐业讲倏v這些系統(tǒng)的新途徑。”
此外，利用這一系統(tǒng)還可幫助控制遺傳工程細(xì)胞對某些致病毒素的反應(yīng)，例如改變細(xì)胞顏色，從而生成非常敏感的生物檢測器。生物通
（生物通：何嬙）
生物通推薦原文摘要：生物通
Load-Induced Modulation of Signal Transduction Networks
Biological signal transduction networks are commonly viewed as circuits that pass along information—in the process amplifying signals, enhancing sensitivity, or performing other signal-processing tasks—to transcriptional and other components. Here, we report on a "reverse-causality" phenomenon, which we call load-induced modulation. Through a combination of analytical and experimental tools, we discovered that signaling was modulated, in a surprising way, by downstream targets that receive the signal and, in doing so, apply what in physics is called a load. Specifically, we found that non-intuitive changes in response dynamics occurred for a covalent modification cycle when load was present. Loading altered the response time of a system, depending on whether the activity of one of the enzymes was maximal and the other was operating at its minimal rate or whether both enzymes were operating at submaximal rates. These two conditions, which we call "limit regime" and "intermediate regime," were associated with increased or decreased response times, respectively. The bandwidth, the range of frequency in which the system can process information, decreased in the presence of load, suggesting that downstream targets participate in establishing a balance between noise-filtering capabilities and a circuit’s ability to process high-frequency stimulation. Nodes in a signaling network are not independent relay devices, but rather are modulated by their downstream targets.

來源：生物通