Nicholson Vincent, Nguyen Kenny, Gollub Edith, McCoy Mary, Yu Feng, Holehouse Alex S, Sukenik Shahar, Boothby Thomas C
Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, USA.
Department of Chemistry and Biochemistry, University of California Merced, Merced, California, USA.
Protein Sci. 2025 Feb;34(2):e70028. doi: 10.1002/pro.70028.
Organisms from all kingdoms of life depend on Late Embryogenesis Abundant (LEA) proteins to survive desiccation. LEA proteins are divided into broad families distinguished by the presence of family-specific motif sequences. The LEA_4 family, characterized by 11-residue motifs, plays a crucial role in the desiccation tolerance of numerous species. However, the role of these motifs in the function of LEA_4 proteins is unclear, with some studies finding that they recapitulate the function of full-length LEA_4 proteins in vivo, and other studies finding the opposite result. In this study, we characterize the ability of LEA_4 motifs to protect a desiccation-sensitive enzyme, citrate synthase (CS), from loss of function during desiccation. We show here that LEA_4 motifs not only prevent the loss of function of CS during desiccation but also that they can do so more robustly via synergistically interactions with cosolutes. Our analysis further suggests that cosolutes induce synergy with LEA_4 motifs in a manner that correlates with transfer free energy. This research advances our understanding of LEA_4 proteins by demonstrating that during desiccation their motifs can protect specific clients to varying degrees and that their protective capacity is modulated by their chemical environment. Our findings extend beyond the realm of desiccation tolerance, offering insights into the interplay between IDPs and cosolutes. By investigating the function of LEA_4 motifs, we highlight broader strategies for understanding protein stability and function.
来自生命各王国的生物体都依赖晚期胚胎发生丰富（LEA）蛋白来在脱水条件下存活。LEA蛋白被分为不同的大家族，这些家族通过特定家族基序序列的存在来区分。以11个残基基序为特征的LEA_4家族在众多物种的耐旱性中起着关键作用。然而，这些基序在LEA_4蛋白功能中的作用尚不清楚，一些研究发现它们在体内重现了全长LEA_4蛋白的功能，而其他研究则得出了相反的结果。在本研究中，我们表征了LEA_4基序保护一种对脱水敏感的酶——柠檬酸合酶（CS）在脱水过程中不丧失功能的能力。我们在此表明，LEA_4基序不仅能防止CS在脱水过程中丧失功能，而且它们可以通过与共溶质的协同相互作用更有力地做到这一点。我们的分析进一步表明，共溶质以与转移自由能相关的方式诱导与LEA_4基序的协同作用。这项研究通过证明在脱水过程中LEA_4蛋白的基序可以在不同程度上保护特定的客户蛋白，并且它们的保护能力受到其化学环境的调节，从而推进了我们对LEA_4蛋白的理解。我们的发现超越了耐旱性领域，为理解内在无序蛋白（IDP）和共溶质之间的相互作用提供了见解。通过研究LEA_4基序的功能，我们突出了理解蛋白质稳定性和功能的更广泛策略。
