Metallochaperone-like genes in Arabidopsis thaliana
Metallochaperone-like genes in Arabidopsis thaliana
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DOI：
10.1039/c003484c
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发表时间：
2010-08-01
期刊：
影响因子：
3.4
通讯作者：
Cobbett, Christopher S.
中科院分区：
文献类型：
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作者：
Tehseen, Muhammad;Cairns, Narelle;Cobbett, Christopher S.
拟南芥中含有预测的 HMA 结构域的金属伴侣蛋白样蛋白的完整清单揭示了一个由 67 种蛋白组成的大家族。 45 种蛋白质（HIPP）具有预测的异戊二烯化位点，而 22 种蛋白质（HPP）则没有。序列比较将蛋白质分为七个主要簇 (I-VII)。簇 IV 值得注意的是在 CysXXCys（金属结合基序）之前存在保守的 Asp 残基，类似于大肠杆菌 ZntA 中的 Zn 结合基序。 HIPP20、HIPP21、HIPP22。对簇 IV 中的 HIPP26 和 HIPP27 进行了更详细的研究。除 HIPP21 外，所有其他均可挽救 Cd 敏感的销售酵母突变体，但未能挽救 zrt1zrt2、zrc1cot1 和 atx1 突变体的生长。在拟南芥中，单突变体和双突变体没有表现出表型，但 hipp20/21/22 三突变体对 Cd 更敏感，并且比野生型积累更少的 Cd，表明 HIPP 可能通过结合 Cd 在 Cd 解毒中发挥作用。启动子-GUS 报告基因表达研究表明这些 HIPP 的表达存在差异。例如，在根中，HIPP22和HIPP26仅在侧根尖中表达，而HIPP20和HIPP25在根脉管系统中表现出强表达。
A complete inventory of metallochaperone-like proteins containing a predicted HMA domain in Arabidopsis revealed a large family of 67 proteins. 45 proteins, the HIPPs, have a predicted isoprenylation site while 22 proteins, the HPPs, do not. Sequence comparisons divided the proteins into seven major clusters (I-VII). Cluster IV is notable for the presence of a conserved Asp residue before the CysXXCys, metal binding motif, analogous to the Zn binding motif in E. coli ZntA. HIPP20, HIPP21, HIPP22. HIPP26 and HIPP27 in Cluster IV were studied in more detail. All but HIPP21 could rescue the Cd-sensitive, sell yeast mutant but failed to rescue the growth of zrt1zrt2, zrc1cot1 and atx1 mutants. In Arabidopsis, single and double mutants did not show a phenotype but the hipp20/21/22 triple mutant was more sensitive to Cd and accumulated less Cd than the wild-type suggesting the HIPPs can have a role in Cd-detoxification, possibly by binding Cd. Promoter-GUS reporter expression studies indicated variable expression of these HIPPs. For example, in roots, HIPP22 and HIPP26 are only expressed in lateral root tips while HIPP20 and HIPP25 show strong expression in the root vasculature.