Putative metal binding site in the transmembrane domain of the manganese transporter SLC30A10 is different from that of related zinc transporters.
Putative metal binding site in the transmembrane domain of the manganese transporter SLC30A10 is different from that of related zinc transporters.
复制标题
DOI：
10.1039/c8mt00115d
复制
发表时间：
2018-08-15
期刊：
影响因子：
--
通讯作者：
Mukhopadhyay S
中科院分区：
文献类型：
--
作者：
Zogzas CE;Mukhopadhyay S
SLC 30蛋白属于金属转运蛋白的阳离子扩散促进剂（CDF）超家族。SLC 30 A10介导锰流出，而其他SLC 30成员转运锌。CDF的金属特异性可由形成跨膜金属结合位点（位点A）的氨基酸赋予。锌转运CDF的A位点，如SLC 30 A1/ZnT 1，具有HXXXD基序，但锰转运蛋白，如SLC 30 A10，具有NXXXD基序。在残基43处的这种关键的组氨酸至天冬酰胺取代被提出为SLC 30 A10的锰转运特异性的基础。然而，我们最近发现，在HeLa细胞中，天冬酰胺-43对锰的流出是有害的;相反，谷氨酸-25，天冬氨酸-40，天冬酰胺-127和天冬氨酸-248是必需的。相反，另一个研究小组报告说，鸡细胞系需要天冬酰胺-43。本研究的目的是解决关于关键天冬酰胺-43残基的需求的分歧结果。为此，我们比较了稳定过表达SLC 30 A10 WT、SLC 30 A10 N43 A或SLC 30 A10 E25 A的四种细胞类型的锰外排活性：生理相关的肝HepG 2和神经元AF 5细胞、HEK细胞和来自Slc 30 a10 −/−小鼠的胚胎成纤维细胞。在所有细胞类型中，SLC 30 A10 N43 A的锰外排活性与WT相当，而SLC 30 A10 E25 A缺乏活性。重要的是，与SLC 30 A10不同，SLC 30 A1/ZnT 1的HXXXD基序的组氨酸残基是锌转运所必需的。这些结果表明，SLC 30 A10的跨膜结构域内的离子配位机制与以前研究的CDF有很大不同，表明位点A残基以外的因素可能赋予CDF金属特异性，并提高了对SLC 30 A10突变引起的锰毒性病理生物学的理解。阳离子扩散促进剂SLC 30 A10转运锰的机制与以前研究的这个超家族中的蛋白质有根本的不同。
SLC30 proteins belong to the cation diffusion facilitator (CDF) superfamily of metal transporters. SLC30A10 mediates manganese efflux, while other SLC30 members transport zinc. Metal specificity of CDFs may be conferred by amino acids that form a transmembrane metal binding site (Site A). Site A of zinc-transporting CDFs, such as SLC30A1/ZnT1, have a HXXXD motif, but manganese transporters, such as SLC30A10, harbor a NXXXD motif. This critical histidine-to-asparagine substitution, at residue 43, was proposed to underlie manganese transport specificity of SLC30A10. However, we recently discovered that asparagine-43 was dispensable for manganese efflux in HeLa cells; instead, glutamate-25, aspartate-40, asparagine-127, and aspartate-248 were required. In contrast, another group reported that asparagine-43 was required in a chicken cell line. The goal of this study was to resolve the divergent results about the requirement of the crucial asparagine-43 residue. For this, we compared the manganese efflux activity of four cell types that stably over-expressed SLC30A10WT, SLC30A10N43A or SLC30A10E25A: physiologically-relevant hepatic HepG2 and neuronal AF5 cells, HEK cells, and embryonic fibroblasts from Slc30a10−/− mice. In all cell types, manganese efflux activity of SLC30A10N43A was comparable to WT, while SLC30A10E25A lacked activity. Importantly, unlike SLC30A10, the histidine residue of the HXXXD motif of SLC30A1/ZnT1 was required for zinc transport. These results imply that the mechanisms of ion coordination within the transmembrane domain of SLC30A10 substantially differ from previously-studied CDFs, suggest that factors beyond Site A residues may confer metal specificity to CDFs, and improve understanding of the pathobiology of manganese toxicity due to mutations in SLC30A10. Mechanism by which the cation diffusion facilitator SLC30A10 transports manganese is fundamentally different from that of previously-studied proteins in this superfamily.
登录
查看更多内容
DOI：
10.1073/pnas.1200362109
发表时间：
2012-05-08
影响因子：
11.1
作者：
Hoch, Eitan;Lin, Wei;Sekler, Israel
通讯作者：
Sekler, Israel
影响因子：
9.8
作者：
Quadri, Marialuisa;Federico, Antonio;Bonifati, Vincenzo
通讯作者：
Bonifati, Vincenzo
影响因子：
3.4
作者：
Mukhopadhyay S
通讯作者：
Mukhopadhyay S
锌转运蛋白YIIP自动调节的结构基础。
影响因子：
16.8
作者：
通讯作者：
--
影响因子：
4.8
作者：
Ohana, Ehud;Hoch, Eitan;Sekler, Israel
通讯作者：
Sekler, Israel