生物通报道  在多细胞生物的细胞社会中，细胞间或细胞内通过高度和地发送与接收信息，并通过放大引起快速的细胞生理反应，或者引起基因活动，引发一系列的细胞生理活动来协调各组织活动，使之成为生命的统一整体对多变的外界环境做出综合反应，这一机制就被称作细胞通讯（Cell communication）。在细胞通讯过程中，靶细胞通过细胞表面受体接收到来自信号传导细胞发送的分子，进而触发靶细胞应答。生物通
近日来自密西根大学医学院和麻省理工学院等机构的研究人员在新研究发现细胞间的通讯并非只是一个单向的信号传导过程，靶细胞可反过来发出接收信息，告诉对方自己所需的信号量。这一发现或可帮助研究人员找到调控细胞信号传导的新途径，对推动合成生物学和癌症转移研究均具有重要的意义。相关研究成果发表在*学术期刊《科学》（Science）旗下子刊《科学信号》（Science Signaling）杂志上。
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领导这一研究的是麻省理工学院生物医学工程学系的副教授Domitilla Del Vecchio。Del Vecchio和他的研究小组早在三年前便提出细胞内的信号系统有可能检测到并对邻近的受体作出信号反应。新研究*次获得了直接的实验数据支持了这一假说。
Del Vecchio称这一效应就像电气或水压系统中的压力阀。例如当你在冲洗马桶时，邻近水的水压可能会随之下降控制水流进入，使水箱中的水量及时得以补充。相类似的是，细胞也会以发送信号分子的方式对一些可变的刺激作出回应，通过调整下游效应器——细胞内受体接受这一信号就可使细胞的响应时间发生改变。
普林斯顿大学化学和生物工程学系教授Stanislav Shvartsman （未参与这一研究）对此评论说：“信号级联反应通常被描述为是单向的。Del Vecchio和他的同事早前的一些研究曾引发了一些争议。新研究借助于精巧设计、开展的实验为他们早期的理论提供了令人信服的数据，并深刻地改变了我们对于细胞内信号传导的理解。”生物通
这一研究发现或有可能帮助研究人员找到控制某些疾病进程的新途径。“近期很多的研究论文都在讨论异常信号对癌症形成的影响，”Vecchio说：“这一发现提供了一个细胞选择信号接受的重要范例，或将促使找到操纵这些系统的新途径。”
此外，利用这一系统还可帮助控制遗传工程细胞对某些致病毒素的反应，例如改变细胞颜色，从而生成非常敏感的生物检测器。生物通
（生物通：何嫱）
生物通推荐原文摘要：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.

来源：生物通