Two related families of metal transferases, ZNG1 and ZNG2, are involved in acclimation to poor Zn nutrition in Arabidopsis

作者：Lifang Zhang, Janeen Braynen, Audrey Fahey, Kriti Chopra, Paolo Cifani, Dimiru Tadesse, Michael Regulski, Fangle Hu, Hubertus J. J. van Dam, Meng Xie, Doreen Ware, Crysten E. Blaby‐Haas · 发表于：Frontiers in Plant Science · 年份：2023 · DOI：10.3389/fpls.2023.1237722 · 被引用次数：11 · 研究领域：Trace Elements in Health、Plant Micronutrient Interactions and Effects、Plant Stress Responses and Tolerance

Metal homeostasis has evolved to tightly modulate the availability of metals within the cell, avoiding cytotoxic interactions due to excess and protein inactivity due to deficiency. Even in the presence of homeostatic processes, however, low bioavailability of these essential metal nutrients in soils can negatively impact crop health and yield. While research has largely focused on how plants assimilate metals, acclimation to metal-limited environments requires a suite of strategies that are not necessarily involved in metal transport across membranes. The identification of these mechanisms provides a new opportunity to improve metal-use efficiency and develop plant foodstuffs with increased concentrations of bioavailable metal nutrients. Here, we investigate the function of two distinct subfamilies of the nucleotide-dependent metallochaperones (NMCs), named ZNG1 and ZNG2, that are found in plants, using Arabidopsis thaliana as a reference organism. AtZNG1 (AT1G26520) is an ortholog of human and fungal ZNG1, and like its previously characterized eukaryotic relatives, localizes to the cytosol and physically interacts with methionine aminopeptidase type I (AtMAP1A). Analysis of At ZNG1 , At MAP1A , At MAP2A , and At MAP2B transgenic mutants are consistent with the role of Arabidopsis ZNG1 as a Zn transferase for AtMAP1A, as previously described in yeast and zebrafish. Structural modeling reveals a flexible cysteine-rich loop that we hypothesize enables direct transfer of Zn fro...