Datta Sandip, Seed Brian
Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, United States of America.
PLoS One. 2018 Jan 19;13(1):e0191152. doi: 10.1371/journal.pone.0191152. eCollection 2018.
Experimental data indicate that stochastic effects exerted at the level of translation contribute substantially to the variation in abundance of proteins expressed at moderate to high levels. This study analyzes the theoretical consequences of fluctuations in residue-specific elongation rates during translation. A simple analytical framework shows that rate variation during elongation gives rise to protein production rates that consist of sums of products of random variables. Simulations show that because the contribution to total variation of products of random variables greatly exceeds that of sums of random variables, the overall distribution exhibits approximately log-normal behavior. Empirical fits of the data can be satisfied by either sums of log-normal distributions, or sums of log-normal and log-logistic distributions. Elongation rate stochastic variation offers an accounting for a major component of biological variation. The analysis provided here highlights a probability distribution that is a natural extension of the Poisson and has broad applicability to many types of multiplicative noise processes.
实验数据表明，在翻译水平上施加的随机效应在很大程度上导致了中度至高水平表达的蛋白质丰度的变化。本研究分析了翻译过程中残基特异性延伸率波动的理论后果。一个简单的分析框架表明，延伸过程中的速率变化会产生由随机变量乘积之和组成的蛋白质产生速率。模拟结果表明，由于随机变量乘积对总变异的贡献大大超过随机变量之和的贡献，整体分布呈现出近似对数正态的行为。数据的经验拟合可以通过对数正态分布之和，或对数正态分布与对数逻辑分布之和来满足。延伸率随机变化为生物变异的一个主要组成部分提供了解释。这里提供的分析突出了一种概率分布，它是泊松分布的自然扩展，并且对许多类型的乘性噪声过程具有广泛的适用性。
