Lack of a Zn/Co substitution ability in the polar diatom Chaetoceros neogracile RS19
Lack of a Zn/Co substitution ability in the polar diatom Chaetoceros neogracile RS19
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DOI：
10.1002/lno.12201
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发表时间：
2022-08
影响因子：
4.5
通讯作者：
Riss M. Kellogg;D. Moran;M. McIlvin;A. Subhas;A. Allen;M. Saito
中科院分区：
文献类型：
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作者：
Riss M. Kellogg;D. Moran;M. McIlvin;A. Subhas;A. Allen;M. Saito
金属酶内必需微量金属锌 (Zn) 和钴 (Co) 的功能替代已在海洋硅藻中得到充分记录，并且已知在不同属和物种中普遍存在。与迄今为止研究的大多数物种相比，我们发现最初从南极洲罗斯海分离出来的极地硅藻 Chaetoceros neogracile RS19 的 Zn 需求无法通过 Co 满足，因此根据生长速率评估，没有表现出 Zn/Co 替代能力。我们使用金属配额和对在一系列锌和钴可用性范围内生长的培养物进行蛋白质组分析，研究了这种硅藻无法使用钴来减轻转运蛋白、传感器/伴侣和金属酶水平上锌限制的生长速率。对总细胞金属配额的分析表明，虽然无法替代，但这种硅藻仍然积极地同化溶解的 Co。我们还观察到，随着介质 Zn2+ 的增加，推定的 α 和 θ-CA、ZIP 转运蛋白、锌指和 Zn 伴侣的丰度水平存在明显的趋势。总体而言，Co 似乎被转运到细胞中，但没有被 Zn 金属酶有效利用。
Functional substitution of the essential trace metals zinc (Zn) and cobalt (Co) within metalloenzymes has been well documented in marine diatoms and is known to be prevalent among varying genera and species. In contrast to the majority of species studied to date, we find that the polar diatom Chaetoceros neogracile RS19, originally isolated from the Ross Sea, Antarctica, has a Zn requirement that cannot be met by Co and thus does not demonstrate a Zn/Co substitution ability as assessed by growth rate. We investigated this diatom's inability to use Co to alleviate Zn‐limited growth rates at the transporter, sensor/chaperone, and metalloenzyme level using metal quota and proteomic analyses of cultures grown over a range of Zn and Co availability. Analysis of total cellular metal quotas revealed that, although incapable of substitution, this diatom still actively assimilated dissolved Co. We furthermore observed distinct trends in the abundance levels of putative α and θ‐CAs, ZIP transporters, Zn fingers, and a Zn chaperone in response to increasing media Zn2+. Overall, Co appears to be transported into the cell, but not efficiently utilized by Zn metalloenzymes.