TSS-seq of either WT or PhyAB mutants for Red light. Arabidopsis thaliana strain:Col-0

Alternative promoter is a potentially proteome-expanding mechanism by which multiple pre-mRNAs are transcribed from a single gene. However, its general impact on the proteome and whether this regulation is intrinsically involved in normal organismal responses, remain unclear. Here we show that the plant photoreceptor phytochrome induces genome-wide alternative promoter changes in Arabidopsis. Consequently, protein isoforms with different N-termini are produced to display light-dependent localization changes, preferentially between plastids and cytoplasm.

可变启动子（Alternative promoter）是一种潜在的可扩展蛋白质组的机制，即单个基因可转录生成多种前体mRNA（pre-mRNA）。然而，其对蛋白质组的整体影响，以及该调控过程是否内在参与正常生物体的应答反应，目前仍不明确。本研究表明，植物光受体光敏色素（phytochrome）可诱导拟南芥（Arabidopsis）发生全基因组范围的可变启动子调控变化。由此产生具有不同N末端（N-terminus）的蛋白质同工型，这类同工型会呈现光依赖的定位改变，且该定位变化优先发生于质体（plastid）与细胞质（cytoplasm）之间。