PDF(Pubmed)
Abstract：
The functional properties of RNA binding proteins (RBPs) require allosteric regulation through interdomain communication. Despite the importance of allostery to biological regulation, only a few studies have been conducted to describe the biophysical nature by which interdomain communication manifests in RBPs. Here, we show for hnRNP A1 that interdomain communication is vital for the unique stability of its amino-terminal domain, which consists of two RNA recognition motifs (RRMs). These RRMs exhibit drastically different stability under pressure. RRM2 unfolds as an individual domain but remains stable when appended to RRM1. Variants that disrupt interdomain communication between the tandem RRMs show a significant decrease in stability. Carrying these mutations over to the full-length protein for in vivo experiments revealed that the mutations affected the ability of the disordered carboxyl-terminal domain to engage in protein-protein interactions and influenced the protein\'s RNA binding capacity. Collectively, this work reveals that thermodynamic coupling between the tandem RRMs of hnRNP A1 accounts for its allosteric regulatory functions.
摘要：
RNA结合蛋白（RBP）的功能特性需要通过域间通讯进行变构调节。尽管变形金刚对生物调节很重要，仅进行了一些研究来描述在RBP中体现域间通讯的生物物理性质。这里,对于hnRNPA1，我们表明域间通讯对于其氨基末端结构域的独特稳定性至关重要，由两个RNA识别基序(RRM)组成。这些RRM在压力下表现出显著不同的稳定性。RRM2作为单个结构域展开,但当附加到RRM1时保持稳定。破坏串联RRM之间的域间通信的变体显示出稳定性的显著降低。将这些突变携带到全长蛋白质进行体内实验表明，突变影响了无序羧基末端结构域参与蛋白质-蛋白质相互作用的能力，并影响了蛋白质的RNA结合能力。总的来说，这项工作揭示了hnRNPA1的串联RRM之间的热力学耦合解释了其变构调节功能。
