共查询到19条相似文献,搜索用时 156 毫秒
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植物铜转运蛋白的结构和功能 总被引:1,自引:0,他引:1
铜(Cu)是植物必需的微量营养元素, 参与植物生长发育过程中的许多生理生化反应。Cu缺乏或过量都会影响植物的正常新陈代谢过程。因此, 植物需要一系列Cu转运蛋白协同作用以保持体内Cu离子的稳态平衡。通常, Cu转运蛋白可分为两类, 即吸收型Cu转运蛋白(如COPT、ZIP和YSL蛋白家族)和排出型Cu转运蛋白(如HMA蛋白家族), 主要负责Cu离子的跨膜转运及调节Cu离子的吸收和排出。然而, 最近有研究表明, 有些Cu伴侣蛋白家族可能是从Cu转运蛋白家族进化而来, 且它们在维持植物细胞Cu离子稳态平衡中也具重要功能。该文对Cu转运蛋白和Cu伴侣蛋白的表达、结构、定位及功能等研究进展进行综述。 相似文献
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植物重金属超富集机理研究进展 总被引:18,自引:2,他引:16
植物超富集重金属机理主要涉及植物对金属离子高的吸收、运输能力,区域化作用及螯合作用等方面,其中跨膜运载蛋白的表达、调控对重金属超富集这一特性起了关键作用。金属阳离子运载蛋白家族主要包括CDF家族、NRAMP家族和ZIP家族等,在超富集植物中已克隆出多个家族的金属运载蛋白基因,这些基因的过量表达对重金属在细胞中的运输、分布和富集及提高植物的抗性方面发挥了重要作用。综述了近年来研究重金属超富集植物吸收、转运和贮存Zn、Ni、Cd等重金属的生理和分子机制所取得的主要进展。 相似文献
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发育中脑惊厥性损伤与海马Zn2+转移 总被引:10,自引:0,他引:10
Zn^2+是一种新的调节神经系统兴奋毒性损伤的离子型介质。积聚于海马苔藓纤维(MF)通路突触前膜囊泡内的Zn^2+,通过特定的自稳态机制向突触后神经元转运,以此实现对大脑兴奋-抑制平衡和认知功能的调节作用。发育中长程或反复惊厥造成海马MF通路Zn^2+的自稳态破坏,Zn^2+在细胞内和突触间发生异常转移,并有再生性发芽等病理损伤现象。Zn^2+转运体、Ca^2+通透性α-氨基-3-羧基-5-甲基异恶唑-4-丙酸(AMPA)/红藻氨酸通道(Ca-A/K通道)、金属结合蛋白和线粒体等共同参与发芽过程中Zn^2+的异常转移。除此之外,Zn^2+亦可作为神经调质,激活信号转导通路,对突触的功能或可塑性产生微妙的影响。这一独特的离子型跨突触信使作用可能具有重要的生理和病理意义。 相似文献
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《中国细胞生物学学报》2010,(2)
必需微量元素锌通过催化和结构作用参与机体多种酶和蛋白功能,与机体发育、脑功能、骨骼生长、生殖健康及免疫功能等密切相关。补充锌可以一定程度防治儿童腹泻、慢性丙型肝炎、急性下呼吸道感染以及感冒等疾病,然而过多的锌具有毒性。因此,机体存在复杂的锌离子稳态体系维持锌离子的吸收、储存和丢失的平衡过程。已发现哺乳动物中SLC39A和SLC30A两个转运蛋白家族直接参与细胞内锌离子的稳态代谢。SLC39A家族又称ZIP家族,共有14个成员,该家族多个成员已被证明可促进细胞外或细胞器内的锌离子转运到细胞质;SLC30A家族又称ZnT家族,共有10个成员,与SLC39A家族功能相反,多个家族成员可协助锌离子从细胞质内流出到细胞外或流进到细胞器内。研究提示ZnT1、ZIP4和ZIP5参与小肠锌离子吸收过程,ZIP10和ZnT1参与肾脏锌离子再吸收过程,ZIP5、ZnT2和ZnT1参与胰腺锌离子分泌丢失过程。另有证据证明SLC39A和SLC30A两个家族的蛋白还可能参与许多疾病包括肿瘤及糖尿病的发生和发展。本文将对哺乳动物SLC39A和SLC30A两个锌转运蛋白家族的最新研究进展进行综述。 相似文献
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《中国细胞生物学学报》2020,(9)
锌(Zn)是人体内含量第二的必需微量金属元素,锌过量或缺失与多种发育缺陷和疾病发生高度相关。细胞内外锌离子转运及稳态维持主要依靠锌转运蛋白来实现。依据锌离子转运方向,锌转运蛋白分为ZIP和ZnT两个家族。锌离子和锌转运蛋白不仅能够作为重要的结构/催化因子调节相关蛋白(特别是酶)的活性,还可以作为信使广泛地参与多种细胞信号转导途径。而与其他功能相比,锌离子和锌转运蛋白作为信号调节因子的研究起步较晚,但近年来进展很快。该文聚焦于ZIP和ZnT家族成员,简要介绍其蛋白结构、分布位置、及转运机制等研究成果,重点总结近年来有关锌转运蛋白直接或间接地(通过调节胞内锌离子)调控细胞信号通路的分子机制的研究进展。 相似文献
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蔡惠罗 《生物化学与生物物理进展》1994,(5)
V型ATP酶广泛存在于细胞内膜系统,如溶酶体,内膜体,高尔基体,分泌颗粒等,V-ATP酶水解ATP,建立跨膜质子电化学梯度(△ ̄μH ̄+),酸化细胞内外环境。研究证明△ ̄μH ̄+和酸化作用为细胞的内吞、外泌、膜流和物质转运等生理生化反应提供了必需的条件。V-ATP酶在生命活动中的重要性和它的实际意义,日益引起人们的兴趣与关注,是当前H ̄-ATP酶家族中一个异常活跃的研究分支。 相似文献
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Sequence similarity and functional relationship among eukaryotic ZIP and CDF transporters 总被引:1,自引:0,他引:1
ZIP (ZRT/IRT-like Protein) and CDF (Cation Diffusion Facilitator) are two large metal transporter families mainly transporting zinc into and out of the cytosol. Several ZIP and CDF transporters have been characterized in mammals and various model organisms, such as yeast, nematode, fruit fly, and zebrafish, and many candidate genes have been identified by genome projects. Unexpected functions of ZIP and CDF transporters have been recently reported in some model organisms, leading to major advances in our understanding of the functions of mammalian counterparts. Here, we review the recent information on the sequence similarity and functional relationship among eukaryotic ZIP and CDF transporters obtained from the representative model organisms. 相似文献
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植物对重金属锌耐性机理的研究进展 总被引:4,自引:1,他引:3
Zn是植物必需的营养元素,同时也是一种常见的有毒重金属元素.由于长期的环境选择和适应进化,植物相应对Zn~(2+)产生了耐性,可减轻或避免Zn~(2+)的毒害.植物对锌耐性机制有:菌根和细胞膜对Zn~(2+)吸收的阻止和控制,其中控制Zn~(2+)的细胞膜跨膜转运器主要有(ZIP)类、阳离子扩散促进器(CDF)类和B-type ATPase (HMA)类;金属硫蛋白(MTs)、植物螯合素(PCs)和有机酸等Zn~(2+)螯合物质的体内螯合解毒;体内区室化分隔以及通过抗氧化系统和渗透调节物质的代谢调节等.本文从生理和分子水平上综述了植物对Zn~(2+)耐性机理的研究进展,并在此基础上提出目前存在的问题和今后研究的重点领域,为该领域的相关研究提供资料和借鉴. 相似文献
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Eukaryotic zinc transporters and their regulation 总被引:49,自引:0,他引:49
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Drosophila fear of intimacy encodes a Zrt/IRT-like protein (ZIP) family zinc transporter functionally related to mammalian ZIP proteins 总被引:2,自引:0,他引:2
Zinc is essential for many cellular processes, and its concentration in the cell must be tightly controlled. The Zrt/IRT-like protein (ZIP) family of zinc transporters have recently been identified as the main regulators of zinc influx into the cytoplasm; however, little is known about their in vivo roles. Previously, we have shown that fear of intimacy (foi) encodes a putative member of the ZIP family that is essential for development in Drosophila. Here we demonstrate that FOI can act as an ion transporter in both yeast and mammalian cell assays and is specific for zinc. We also provide insight into the mechanism of action of the ZIP family through membrane topology and structure-function analyses of FOI. Our work demonstrates that Drosophila FOI is closely related to mammalian ZIP proteins at the functional level and that Drosophila represents an ideal system for understanding the in vivo roles of this family. In addition, this work indicates that the control of zinc by ZIP transporters may play a critical role in regulating developmental processes. 相似文献
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Zinc content in rat lateral prostate (LP) is higher compared with the other tissues, but the zinc retention system in the
prostate remains unclear. In the present study, we examined the expression of ZRT, and IRT-like protein (ZIP) family transporter
in rat prostate. The zinc level in rat LP was higher compared with the ventral (VP) and dorsal prostate (DP). The predicted
ZIP2 mRNA was really expressed in LP at a high level. The expression was decreased in LP from castrated rats, associated with
a decrease in zinc level, and these changes were prevented by testosterone replacement. Moreover, ZIP2 expression levels in
LP positively correlated with the zinc levels. These findings strongly suggest that ZIP2 is involved in zinc homeostasis of
rat prostate. 相似文献
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The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2′-deoxycytidine (AZA) increased intracellular (after 24 and 48 h) and total cellular zinc levels (after 48 h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48 h. MT mRNA was significantly enhanced after 24 h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells. 相似文献
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Brittany L. Steimle Danielle K. Bailey Frances M. Smith Shaina L. Rosenblum Daniel J. Kosman 《The Journal of biological chemistry》2022,298(8)
Manganese (II) accumulation in human brain microvascular endothelial cells is mediated by the metal-ion transporters ZRT IRT-like protein 8 (ZIP8) and ZRT IRT-like protein 14 (ZIP14). The plasma membrane occupancy of ZIP14, in particular, is increased in cells treated with Mn2+, lipopolysaccharide, or IL-6, but the mechanism of this regulation has not been elucidated. The calcium-transporting type 2C member 1 ATPase, SPCA1, is a Golgi-localized Ca2+-uptake transporter thought to support Golgi uptake of Mn2+ also. Here, we show using surface protein biotinylation, indirect immunofluorescence, and GFP-tagged proteins that cytoplasmic Ca2+ regulates ZIP8- and ZIP14-mediated manganese accumulation in human brain microvascular endothelial cells by increasing the plasma membrane localization of these transporters. We demonstrate that RNAi knockdown of SPCA1 expression results in an increase in cytoplasmic Ca2+ levels. In turn, we found increased cytoplasmic Ca2+ enhances membrane-localized ZIP8 and ZIP14 and a subsequent increase in 54Mn2+ uptake. Furthermore, overexpression of WT SPCA1 or a gain-of-function mutant resulted in a decrease in cytoplasmic Ca2+ and 54Mn2+ accumulation. While addition of Ca2+ positively regulated ZIP-mediated 54Mn2+ uptake, we show chelation of Ca2+ diminished manganese transport. In conclusion, the modulation of ZIP8 and ZIP14 membrane cycling by cytoplasmic calcium is a novel finding and provides new insight into the regulation of the uptake of Mn2+ and other divalent metal ions–mediated ZIP metal transporters. 相似文献