生物通報道  在多細胞生物的細胞社會中，細胞間或細胞內通過高度和地發送與接收信息，并通過放大引起快速的細胞生理反應，或者引起基因活動，引發一系列的細胞生理活動來協調各組織活動，使之成為生命的統一整體對多變的外界環境做出綜合反應，這一機制就被稱作細胞通訊（Cell communication）。在細胞通訊過程中，靶細胞通過細胞表面受體接收到來自信號傳導細胞發送的分子，進而觸發靶細胞應答。生物通
近日來自密西根大學醫學院和麻省理工學院等機構的研究人員在新研究發現細胞間的通訊并非只是一個單向的信號傳導過程，靶細胞可反過來發出接收信息，告訴對方自己所需的信號量。這一發現或可幫助研究人員找到調控細胞信號傳導的新途徑，對推動合成生物學和癌癥轉移研究均具有重要的意義。相關研究成果發表在*學術期刊《科學》（Science）旗下子刊《科學信號》（Science Signaling）雜志上。
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領導這一研究的是麻省理工學院生物醫學工程學系的副教授Domitilla Del Vecchio。Del Vecchio和他的研究小組早在三年前便提出細胞內的信號系統有可能檢測到并對鄰近的受體作出信號反應。新研究*次獲得了直接的實驗數據支持了這一假說。
Del Vecchio稱這一效應就像電氣或水壓系統中的壓力閥。例如當你在沖洗馬桶時，鄰近水的水壓可能會隨之下降控制水流進入，使水箱中的水量及時得以補充。相類似的是，細胞也會以發送信號分子的方式對一些可變的刺激作出回應，通過調整下游效應器——細胞內受體接受這一信號就可使細胞的響應時間發生改變。
普林斯頓大學化學和生物工程學系教授Stanislav Shvartsman （未參與這一研究）對此評論說：“信號級聯反應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了一些爭議。新研究借助于精巧設計、開展的實驗為他們早期的理論提供了令人信服的數據，并深刻地改變了我們對于細胞內信號傳導的理解。”生物通
這一研究發現或有可能幫助研究人員找到控制某些疾病進程的新途徑。“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：“這一發現提供了一個細胞選擇信號接受的重要范例，或將促使找到操縱這些系統的新途徑。”
此外，利用這一系統還可幫助控制遺傳工程細胞對某些致病毒素的反應，例如改變細胞顏色，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