From the Department of Animal and Avian Sciences and.
the Redox Biology Center, Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588.
J Biol Chem. 2018 Jul 13;293(28):10911-10925. doi: 10.1074/jbc.RA118.003503. Epub 2018 May 21.
Copper plays key roles in catalytic and regulatory biochemical reactions essential for normal growth, development, and health. Dietary copper deficiencies or mutations in copper homeostasis genes can lead to abnormal musculoskeletal development, cognitive disorders, and poor growth. In yeast and mammals, copper is acquired through the activities of the CTR1 family of high-affinity copper transporters. However, the mechanisms of systemic responses to dietary or tissue-specific copper deficiency remain unclear. Here, taking advantage of the animal model for studying whole-body copper homeostasis, we investigated the role of a CTR1 homolog, CHCA-1, in copper acquisition and in worm growth, development, and behavior. Using sequence homology searches, we identified 10 potential orthologs to mammalian Among these genes, we found that , which is transcriptionally up-regulated in the intestine and hypodermis of during copper deficiency, is required for normal growth, reproduction, and maintenance of systemic copper balance under copper deprivation. The intestinal copper transporter CUA-1 normally traffics to endosomes to sequester excess copper, and we found here that loss of caused CUA-1 to mislocalize to the basolateral membrane under copper overload conditions. Moreover, animals lacking exhibited significantly reduced copper avoidance behavior in response to toxic copper conditions compared with WT worms. These results establish that CHCA-1-mediated copper acquisition in is crucial for normal growth, development, and copper-sensing behavior.
铜在催化和调节生物化学反应中起着关键作用,这些反应对于正常的生长、发育和健康是必不可少的。膳食铜缺乏或铜稳态基因的突变可导致骨骼肌肉发育异常、认知障碍和生长不良。在酵母和哺乳动物中,铜是通过高亲和力铜转运蛋白 CTR1 家族的活性获得的。然而,机体对膳食或组织特异性铜缺乏的系统反应机制尚不清楚。在这里,我们利用研究全身铜稳态的动物模型,研究了 CTR1 同源物 CHCA-1 在铜摄取以及蠕虫生长、发育和行为中的作用。通过序列同源性搜索,我们鉴定了 10 个哺乳动物的潜在同源基因。在这些基因中,我们发现,在铜缺乏时,在肠道和皮下组织中转录上调的,对于在铜剥夺条件下正常生长、繁殖和维持全身铜平衡是必需的。肠道铜转运蛋白 CUA-1 通常转运到内体以隔离多余的铜,我们在这里发现,缺失导致 CUA-1 在铜过载条件下错误定位于基底外侧膜。此外,与 WT 蠕虫相比,缺乏的动物在应对有毒铜条件时表现出明显减少的铜回避行为。这些结果表明,CHCA-1 介导的铜摄取在铜稳态行为中对于正常生长、发育是至关重要的。