Biochimica et Biophysica Acta-Bioenergetics最新文献_第6页

Species differences in glycerol-3-phosphate metabolism reveals trade-offs between metabolic adaptations and cell proliferation 甘油-3-磷酸代谢的物种差异揭示了代谢适应和细胞增殖之间的权衡。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-04-01 Epub Date: 2024-12-02 DOI: 10.1016/j.bbabio.2024.149530

Kateryna Gaertner , Mügen Terzioglu , Craig Michell , Riikka Tapanainen , Jaakko Pohjoismäki , Eric Dufour , Sina Saari

The temperate climate-adapted brown hare (Lepus europaeus) and the cold-adapted mountain hare (Lepus timidus) are closely related and interfertile species. However, their skin fibroblasts display distinct gene expression profiles related to fundamental cellular processes. This indicates important metabolic divergence between the two species. Through targeted metabolomics and metabolite tracing, we identified species-specific variations in glycerol 3-phosphate (G3P) metabolism. G3P is a key metabolite of the G3P shuttle, which transfers reducing equivalents from cytosolic NADH to the mitochondrial electron transport chain (ETC), consequently regulating glycolysis, lipid metabolism, and mitochondrial bioenergetics. Alterations in G3P metabolism have been implicated in multiple human pathologies including cancer and diabetes. We observed that mountain hare mitochondria exhibit elevated G3P shuttle activity, alongside increased membrane potential and decreased mitochondrial temperature. Silencing mitochondrial G3P dehydrogenase (GPD2), which couples the conversion of G3P to the ETC, uncovered its species-specific role in controlling mitochondrial membrane potential and highlighted its involvement in skin fibroblast thermogenesis. Unexpectedly, GPD2 silencing enhanced wound healing and cell proliferation rates in a species-specific manner. Our study underscores the pivotal role of the G3P shuttle in mediating physiological, bioenergetic, and metabolic divergence between these hare species.

温带适应的褐兔（Lepus europaeus）和寒冷适应的山地兔（Lepus timidus）是亲缘关系密切的杂交物种。然而，他们的皮肤成纤维细胞显示出与基本细胞过程相关的不同基因表达谱。这表明两个物种之间存在重要的代谢差异。通过靶向代谢组学和代谢物追踪，我们确定了甘油3-磷酸（G3P）代谢的物种特异性变化。G3P是G3P穿梭的关键代谢物，它将还原性等价物从胞质NADH转移到线粒体电子传递链（ETC），从而调节糖酵解、脂质代谢和线粒体生物能量学。G3P代谢的改变与包括癌症和糖尿病在内的多种人类疾病有关。我们观察到，山梨线粒体G3P穿梭活性升高，同时膜电位升高，线粒体温度降低。沉默线粒体G3P脱氢酶（GPD2），发现其在控制线粒体膜电位中的物种特异性作用，并强调其参与皮肤成纤维细胞产热。GPD2将G3P转化为ETC偶联。出乎意料的是，GPD2沉默以物种特异性的方式增强了伤口愈合和细胞增殖率。我们的研究强调了G3P穿梭在调节这些物种之间的生理、生物能量和代谢差异中的关键作用。

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引用次数: 0

Circadian clockwork controls the balance between mitochondrial turnover and dynamics: What is life … without time marking? 生物钟控制着线粒体更新和动态之间的平衡：没有时间标记的生命是什么？

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-04-01 Epub Date: 2025-01-27 DOI: 10.1016/j.bbabio.2025.149542

Olga Cela , Rosella Scrima , Michela Rosiello , Consiglia Pacelli , Claudia Piccoli , Mirko Tamma , Francesca Agriesti , Gianluigi Mazzoccoli , Nazzareno Capitanio

Circadian rhythms driven by biological clocks regulate physiological processes in all living organisms by anticipating daily geophysical changes, thus enhancing environmental adaptation. Time-resolved serial multi-omic analyses in vivo, ex vivo, and in synchronized cell cultures have revealed rhythmic changes in the transcriptome, proteome, and metabolome, involving up to 50 % of the mammalian genome. Mitochondrial oxidative metabolism is central to cellular bioenergetics, and many nuclear genes encoding mitochondrial proteins exhibit both circadian and ultradian oscillatory expression. However, studies on mitochondrial DNA (mtDNA) gene expression remain incomplete. Using a well-established in vitro synchronization protocol, we investigated the time-resolved expression of mtDNA genes coding for respiratory chain complex subunits, revealing a rhythmic profile dependent on BMAL1, the master circadian clock transcription factor. Additionally, the expression of genes coding for key mitochondrial biogenesis transcription factors, PGC1a, NRF1, and TFAM, showed BMAL1-dependent circadian oscillations. Notably, LC3-II, involved in mitophagy, displayed a similar in-phase circadian expression, thereby maintaining stable respiratory chain complex levels. Moreover, we found that simultaneous mitochondrial biogenesis and degradation occur in a coordinated manner with cycles in organelle dynamics, leading to rhythmic changes in mitochondrial fission and fusion. This study provides new insights into circadian clock regulation of mitochondrial turnover, emphasizing the importance of temporal regulation in cellular metabolism. Understanding these mechanisms opens potential therapeutic avenues for targeting mitochondrial dysfunctions and related metabolic disorders.

生物时钟驱动的昼夜节律通过预测地球物理的日常变化来调节所有生物的生理过程，从而增强环境适应能力。在体内、离体和同步细胞培养中进行的时间分辨系列多组学分析揭示了转录组、蛋白质组和代谢组的节律性变化，涉及高达50% %的哺乳动物基因组。线粒体氧化代谢是细胞生物能量学的核心，许多编码线粒体蛋白的核基因表现出昼夜节律和超振荡表达。然而，对线粒体DNA （mtDNA）基因表达的研究仍然不完整。利用一种完善的体外同步方案，我们研究了编码呼吸链复合物亚基的mtDNA基因的时间分辨表达，揭示了依赖于主昼夜节律时钟转录因子BMAL1的节律谱。此外，编码关键线粒体生物发生转录因子PGC1a、NRF1和TFAM的基因表达显示出bmal1依赖的昼夜节律振荡。值得注意的是，参与有丝分裂的LC3-II表现出类似的同相昼夜节律表达，从而维持稳定的呼吸链复合物水平。此外，我们发现线粒体的生物发生和降解与细胞器动力学的周期协调发生，导致线粒体裂变和融合的节律变化。这项研究为线粒体转换的生物钟调节提供了新的见解，强调了时间调节在细胞代谢中的重要性。了解这些机制为针对线粒体功能障碍和相关代谢紊乱开辟了潜在的治疗途径。

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引用次数: 0

Alternative NADH dehydrogenase: A complex I backup, a drug target, and a tool for mitochondrial gene therapy 替代NADH脱氢酶：一种复合体I备份，一种药物靶点，以及线粒体基因治疗的工具。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-04-01 Epub Date: 2024-11-28 DOI: 10.1016/j.bbabio.2024.149529

Dmytro V. Gospodaryov

Alternative NADH dehydrogenase, also known as type II NADH dehydrogenase (NDH-2), catalyzes the same redox reaction as mitochondrial respiratory chain complex I. Specifically, it oxidizes reduced nicotinamide adenine dinucleotide (NADH) while simultaneously reducing ubiquinone to ubiquinol. However, unlike complex I, this enzyme is non-proton pumping, comprises of a single subunit, and is resistant to rotenone. Initially identified in bacteria, fungi and plants, NDH-2 was subsequently discovered in protists and certain animal taxa including sea squirts. The gene coding for NDH-2 is also present in the genomes of some annelids, tardigrades, and crustaceans. For over two decades, NDH-2 has been investigated as a potential substitute for defective complex I. In model organisms, NDH-2 has been shown to ameliorate a broad spectrum of conditions associated with complex I malfunction, including symptoms of Parkinson's disease. Recently, lifespan extension has been observed in animals expressing NDH-2 in a heterologous manner. A variety of mechanisms have been put forward by which NDH-2 may extend lifespan. Such mechanisms include the activation of pro-longevity pathways through modulation of the NAD⁺/NADH ratio, decreasing production of reactive oxygen species (ROS) in mitochondria, or then through moderate increases in ROS production followed by activation of defense pathways (mitohormesis). This review gives an overview of the latest research on NDH-2, including the structural peculiarities of NDH-2, its inhibitors, its role in the pathogenicity of mycobacteria and apicomplexan parasites, and its function in bacteria, fungi, and animals.

选择性NADH脱氢酶，也称为II型NADH脱氢酶（NDH-2），催化与线粒体呼吸链复合体i相同的氧化还原反应。具体来说，它在氧化还原性烟酰胺腺嘌呤二核苷酸（NADH）的同时将泛醌还原为泛醇。然而，与复合物I不同的是，这种酶是非质子泵送的，由单个亚基组成，并且对鱼藤酮具有抗性。NDH-2最初在细菌、真菌和植物中被发现，随后在原生生物和包括海鞘在内的某些动物分类群中被发现。编码NDH-2的基因也存在于一些环节动物、缓步动物和甲壳类动物的基因组中。二十多年来，人们一直在研究NDH-2作为复合物I缺陷的潜在替代品。在模式生物中，NDH-2已被证明可以改善与复合物I功能障碍相关的广泛疾病，包括帕金森病的症状。近年来，在异源表达NDH-2的动物中观察到寿命延长。NDH-2延长寿命的多种机制已被提出。这些机制包括通过调节NAD+/NADH比率激活促长寿途径，减少线粒体中活性氧（ROS）的产生，或者通过适度增加ROS的产生，随后激活防御途径（有丝分裂）。本文综述了NDH-2的最新研究进展，包括NDH-2的结构特点、抑制剂、在分枝杆菌和顶复体寄生虫的致病性中的作用以及在细菌、真菌和动物中的作用。

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引用次数: 0

Acute treadmill exercise induces mitochondrial unfolded protein response in skeletal muscle of male rats 急性跑步机运动诱导雄性大鼠骨骼肌线粒体未折叠蛋白反应。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-04-01 Epub Date: 2024-12-13 DOI: 10.1016/j.bbabio.2024.149532

Ibrahim Turkel , Gokhan Burcin Kubat , Tugba Fatsa , Ozgu Acet , Berkay Ozerklig , Burak Yazgan , Gulcin Simsek , Keshav K. Singh , Sukran Nazan Kosar

Mitochondria are often referred to as the energy centers of the cell and are recognized as key players in signal transduction, sensing, and responding to internal and external stimuli. Under stress conditions, the mitochondrial unfolded protein response (UPR^mt), a conserved mitochondrial quality control mechanism, is activated to maintain mitochondrial and cellular homeostasis. As a physiological stimulus, exercise-induced mitochondrial perturbations trigger UPR^mt, coordinating mitochondria-to-nucleus communication and initiating a transcriptional program to restore mitochondrial function. The aim of this study was to evaluate the UPR^mt signaling response to acute exercise in skeletal muscle. Male rats were subjected to acute treadmill exercise at 25 m/min for 60 min on a 0 % grade. Plantaris muscles were collected from both sedentary and exercise groups at various times: immediately (0), and at 1, 3, 6, 12, and 24 h post-exercise. Reactive oxygen species (ROS) production was assessed using hydrogen peroxide assay and dihydroethidium staining. Additionally, the mRNA and protein expression of UPR^mt markers were measured using ELISA and real-time PCR. Mitochondrial activity was assessed using succinate dehydrogenase (SDH) and cytochrome c oxidase (COX) staining. Our results demonstrated that acute exercise increased ROS production and upregulated UPR^mt markers at both gene and protein levels. Moreover, skeletal muscle exhibited an increase in mitochondrial activity in response to exercise, as indicated by SDH and COX staining. These findings suggest that acute treadmill exercise is sufficient to induce ROS production, activate UPR^mt signaling, and enhance mitochondrial activity in skeletal muscle, expanding our understanding of mitochondrial adaptations to exercise.

线粒体通常被称为细胞的能量中心，被认为是信号转导、感知和响应内外刺激的关键角色。在压力条件下，线粒体未折叠蛋白反应（UPRmt）--一种保守的线粒体质量控制机制--会被激活，以维持线粒体和细胞的平衡。作为一种生理刺激，运动诱导的线粒体扰动会触发 UPRmt，协调线粒体与细胞核之间的交流并启动转录程序以恢复线粒体功能。本研究旨在评估骨骼肌对急性运动的 UPRmt 信号反应。雄性大鼠在 0% 的坡度上以 25 米/分钟的速度进行急性跑步机运动 60 分钟。在不同时间收集静坐组和运动组大鼠的足底肌肉：运动后立即（0）、1、3、6、12 和 24 小时。使用过氧化氢测定法和二氢乙锭染色法评估活性氧（ROS）的产生。此外，还使用 ELISA 和实时 PCR 测量了 UPRmt 标记的 mRNA 和蛋白质表达。线粒体活性通过琥珀酸脱氢酶（SDH）和细胞色素c氧化酶（COX）染色进行评估。我们的研究结果表明，急性运动会导致 ROS 生成增加，并在基因和蛋白质水平上上调 UPRmt 标记。此外，SDH 和 COX 染色显示，骨骼肌的线粒体活性在运动后有所增加。这些研究结果表明，急性跑步机运动足以诱导 ROS 生成、激活 UPRmt 信号转导并增强骨骼肌线粒体的活性，从而拓展了我们对线粒体适应运动的认识。

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引用次数: 0

Purification and characterization of recombinant human mitochondrial proton-pumping nicotinamide nucleotide transhydrogenase 重组人线粒体抽质子烟酰胺核苷酸转氢酶的纯化及特性研究。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-04-01 Epub Date: 2025-01-17 DOI: 10.1016/j.bbabio.2025.149540

Sangjin Hong , Simone Graf , Christoph von Ballmoos , Robert B. Gennis

The human mitochondrial nicotinamide nucleotide transhydrogenase (NNT) uses the proton motive force to drive hydride transfer from NADH to NADP⁺ and is a major contributor to the generation of mitochondrial NADPH. NNT plays a critical role in maintaining cellular redox balance. NNT-deficiency results in oxidative damage and its absence results in familial glucocorticoid deficiency. Recently it has also become clear that NNT is a tumor promoter whose presence in mouse models of non-small cell lung cancer results in enhanced tumor growth and aggressiveness. The presence of NNT mitigates the effects of oxidative stress and facilitates cancer cell proliferation, suggesting NNT-inhibition as a promising therapeutic strategy. The human NNT is a homodimer in which each subunit has a molecular weight of 114 kDa and 14 transmembrane spans. Here we report on the development of a system for isolating full-length recombinant human NNT using Escherichia coli. The purified enzyme is catalytically active, and the enzyme reconstituted into proteoliposomes pumps protons and generates a proton motive force capable of driving ATP synthesis by E. coli ATP synthase. The recombinant human NNT will facilitate structural and biochemical studies as well as provide a useful tool to develop and characterize potential anti-cancer therapeutics.

人类线粒体烟酰胺核苷酸转氢酶（NNT）利用质子动力驱动氢化物从NADH向NADP+转移，是线粒体NADPH生成的主要贡献者。NNT在维持细胞氧化还原平衡中起关键作用。nnt缺乏导致氧化损伤，其缺失导致家族性糖皮质激素缺乏。最近也清楚地表明，NNT是一种肿瘤启动子，其在非小细胞肺癌小鼠模型中的存在导致肿瘤生长和侵袭性增强。NNT的存在减轻了氧化应激的影响，促进了癌细胞的增殖，这表明抑制NNT是一种很有前途的治疗策略。人类NNT是一种同源二聚体，其中每个亚基的分子量为114 kDa，跨膜跨度为14。在这里，我们报告了一种利用大肠杆菌分离全长重组人NNT的系统。纯化后的酶具有催化活性，重组为蛋白脂质体的酶泵送质子并产生质子动力，能够驱动大肠杆菌ATP合酶合成ATP。重组人NNT将促进结构和生化研究，并为开发和表征潜在的抗癌治疗方法提供有用的工具。

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引用次数: 0

An analysis of the structural changes of the oxygen evolving complex of Photosystem II in the S1 and S3 states revealed by serial femtosecond crystallography 用连续飞秒晶体学分析光系统II的S1和S3态析氧配合物的结构变化。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-04-01 Epub Date: 2024-12-16 DOI: 10.1016/j.bbabio.2024.149531

Salma Yehia , Jimin Wang , Gary W. Brudvig , M.R. Gunner , Bernard R. Brooks , Muhamed Amin

Photosystem II (PSII) is a unique natural catalyst that converts solar energy into chemical energy using earth abundant elements in water at physiological pH. Understanding the reaction mechanism will aid the design of biomimetic artificial catalysts for efficient solar energy conversion. The Mn₄O₅Ca cluster cycles through five increasingly oxidized intermediates before oxidizing two water molecules into O₂ and releasing protons to the lumen and electrons to drive PSII reactions. The Mn coordination and OEC electronic structure changes through these intermediates. Thus, obtaining a high-resolution structure of each catalytic intermediate would help reveal the reaction mechanism. While valuable structural information was obtained from conventional X-ray crystallography, time-resolution of conventional X-ray crystallography limits the analysis of shorted-lived reaction intermediates. Serial Femtosecond X-ray crystallography (SFX), which overcomes the radiation damage by using ultra short laser pulse for imaging, has been used extensively to study the water splitting intermediates in PSII. Here, we review the state of the art and our understanding of the water splitting reaction before and after the advent of SFX. Furthermore, we analyze the likely Mn coordination in multiple XFEL structures prepared in the dark-adapted S₁ state and those following two-flashes which are poised in the penultimate S₃ oxidation state based on Mn coordination chemistry. Finally, we summarize the major contributions of the SFX to our understanding of the structures of the S₁ and S₃ states.

光系统II （Photosystem II， PSII）是一种独特的天然催化剂，利用水中富土元素在生理ph下将太阳能转化为化学能，了解其反应机理将有助于设计高效太阳能转化的仿生人工催化剂。Mn4O5Ca簇通过5个日益氧化的中间体循环，然后将两个水分子氧化成O2，并向管腔释放质子和电子来驱动PSII反应。Mn配位和OEC电子结构通过这些中间体发生改变。因此，获得每个催化中间体的高分辨率结构将有助于揭示反应机理。虽然从传统的x射线晶体学中获得了有价值的结构信息，但传统x射线晶体学的时间分辨率限制了对短寿命反应中间体的分析。连续飞秒x射线晶体学（SFX）利用超短激光脉冲成像克服了辐射损伤，被广泛用于研究PSII中水分裂中间体。在这里，我们回顾了SFX出现前后的艺术状态和我们对水分解反应的理解。此外，基于Mn配位化学，我们分析了在适应黑暗的S1态和两次闪光后处于倒数第二S3氧化态的多个XFEL结构中可能的Mn配位。最后，我们总结了SFX对我们理解S1和S3态结构的主要贡献。

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引用次数: 0

Identification of determinants for variability in mitochondrial biochemical complex activities 鉴定线粒体生化复合体活动变异的决定因素

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-04-01 Epub Date: 2025-03-09 DOI: 10.1016/j.bbabio.2025.149553

Sandra Monica Bach de Courtade , Marte Eikenes , Ying Sheng , Tuula A. Nyman , Yngve Thomas Bliksrud , Katja Scheffler , Lars Eide

Diagnostics of mitochondrial disease requires a combination of clinical evaluations and biochemical characterization. However, the large normal variation in mitochondrial complex activity limits the precision of biochemical diagnostics. Thus, identifying factors that contribute to such variations could enhance diagnostic accuracy. In comparison, inbred mice demonstrate much less variations in brain mitochondrial activity, but a clear reduction with age. Interestingly, pretreatment of mouse brain mitochondria with the detergent dodecyl maltoside abolishes the reduction. We therefore postulated that DDM pretreatment could be valuable tool for distinguishing between variations caused by posttranslational modifications and those caused by genetic heterogeneity.

In this study, we evaluated the effects of age, DDM sensitivity, oxidative damage and single nucleotide polymorphism on biochemical complex activity and the proteome of human muscle mitochondria, which serve as reference standards for mitochondrial diagnostics. Our results indicate that mtDNA variants are the primary contributors to the diversity in biochemical activity in human muscle mitochondria from healthy individuals.

线粒体疾病的诊断需要结合临床评估和生化表征。然而，线粒体复合体活性的巨大正常变异限制了生化诊断的准确性。因此，识别导致这些变化的因素可以提高诊断的准确性。相比之下，近亲繁殖的老鼠大脑线粒体活动的变化要小得多，但随着年龄的增长明显减少。有趣的是，用洗涤剂十二烷基麦芽糖苷预处理小鼠脑线粒体可以消除这种还原。因此，我们假设DDM预处理可能是区分翻译后修饰引起的变异和遗传异质性引起的变异的有价值的工具。在本研究中，我们评估了年龄、DDM敏感性、氧化损伤和单核苷酸多态性对人类肌肉线粒体生化复合物活性和蛋白质组的影响，为线粒体诊断提供参考标准。我们的研究结果表明，mtDNA变异是健康个体人类肌肉线粒体生化活性多样性的主要贡献者。

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引用次数: 0

Ultrafast kinetics of PSI-LHCI super-complex from the moss Physcomitrella patens 青苔Physcomitrella patens的PSI-LHCI超级复合物的超快动力学。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-01-01 Epub Date: 2024-11-17 DOI: 10.1016/j.bbabio.2024.149526

Dongyang Liu , Qiujing Yan , Xiaochun Qin , Lijin Tian

Photosystem I (PSI) is a large membrane photosynthetic complex that harvests sunlight and drives photosynthetic electron transport. In both green algae and higher plants, PSI's ultrafast energy transfer and charge separation kinetics have been characterized. In contrast, it is not yet clear in Physcomitrella patens, even though moss is one of the earliest land plants and represents a critical stage in plant evolution. Here, we measured the time-resolved fluorescence of purified Pp PSI-LHCI at both room temperature (RT) and 77 K. Compared to the PSI kinetics of Arabidopsis thaliana at RT, we found that although the overall trapping time of Pp PSI-LHCI is nearly identical, ∼46 ps, their lifetimes at different wavelength regions differ. Specifically, Pp PSI-LHCI is slower in energy trapping below 720 nm but faster beyond. The slow-down of energy transfer between bulk chlorophylls (Chls, <720 nm) in Pp PSI-LHCI is probably because of the larger spatial gap between the PSI core and LHCI belt, and the acceleration of trapping at longer wavelength is most likely due to the lack of low-energy red-shifted Chls (red Chls). Indeed, time-resolved fluorescence results at 77 K revealed only three types of red Chls of 702 nm, 712 nm, and 720 nm in Pp PSI-LHCI but failed to detect the red Chls of 735 nm that present in LHCI in higher plants. Finally, we briefly discussed the evolutionary adaptations of PSI-LHCI in the context of red Chls from green algae to mosses and to land plants.

光系统 I（PSI）是一个大型膜光合复合体，它能捕获阳光并驱动光合电子传递。在绿藻和高等植物中，PSI 的超快能量转移和电荷分离动力学都已得到表征。相比之下，尽管苔藓是最早的陆地植物之一，代表着植物进化的一个关键阶段，但它在青苔（Physcomitrella patens）中的情况尚不清楚。在这里，我们测量了纯化的 Pp PSI-LHCI 在室温（RT）和 77 K 下的时间分辨荧光。与拟南芥在室温下的 PSI 动力学相比，我们发现虽然 Pp PSI-LHCI 的总体捕获时间几乎相同（约 46 ps），但它们在不同波长区域的寿命却不同。具体来说，Pp PSI-LHCI 在 720 纳米以下的能量捕获较慢，但在 720 纳米以上的能量捕获较快。大量叶绿素（Chls、

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引用次数: 0

The small membrane protein CcoS is involved in cofactor insertion into the cbb3-type cytochrome c oxidase 小膜蛋白 CcoS 参与了辅助因子插入 cbb3 型细胞色素 c 氧化酶的过程。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-01-01 Epub Date: 2024-11-14 DOI: 10.1016/j.bbabio.2024.149524

Juna Rauch , Katharina Kurscheidt , Kai-Wei Shen , Andreea Andrei , Noel Daum , Yavuz Öztürk , Frederic Melin , Gunhild Layer , Petra Hellwig , Fevzi Daldal , Hans-Georg Koch

Respiratory complexes, such as cytochrome oxidases, are cofactor-containing multi-subunit protein complexes that are critically important for energy metabolism in all domains of life. Their intricate assembly strictly depends on accessory proteins, which coordinate subunit associations and cofactor deliveries. The small membrane protein CcoS was previously identified as an essential assembly factor to produce an active cbb₃-type cytochrome oxidase (cbb₃-Cox) in Rhodobacter capsulatus, but its function remained unknown. Here we show that the ΔccoS strain assembles a heme b deficient cbb₃-Cox, in which the CcoN-CcoO subunit association is impaired. Chemical crosslinking demonstrates that CcoS interacts with the CcoN and CcoP subunits of cbb₃-Cox, and that it stabilizes the interaction of the Cu-chaperone SenC with cbb₃-Cox. CcoS lacks heme- or Cu-binding motifs, and we did not find evidence for direct heme or Cu binding; rather our data indicate that CcoS, together with SenC, coordinates heme and Cu insertion into cbb₃-Cox.

细胞色素氧化酶等呼吸复合体是含辅因子的多亚基蛋白质复合体，对生命各领域的能量代谢至关重要。它们错综复杂的组装严格依赖于附属蛋白，后者协调亚基的结合和辅助因子的运送。以前曾发现小膜蛋白 CcoS 是在荚膜罗杆菌中产生活性 cbb3 型细胞色素氧化酶（ccb3-Cox）的重要组装因子，但其功能仍然未知。在这里，我们发现ΔccoS菌株能组装出缺乏血红素b的ccb3-Cox，其中CcoN-CcoO亚基的结合受到损害。化学交联证明，CcoS 与 cbb3-Cox 的 CcoN 和 CcoP 亚基相互作用，并能稳定 Cu 合子 SenC 与 cbb3-Cox 的相互作用。CcoS 缺乏血红素或 Cu 结合基团，我们也没有发现直接与血红素或 Cu 结合的证据；相反，我们的数据表明，CcoS 与 SenC 一起协调血红素和 Cu 插入 cbb3-Cox。

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引用次数: 0

Lysine 204 is crucial for the antiport function of the human LAT1 transporter 赖氨酸 204 对人类 LAT1 转运体的反转运功能至关重要。

IF 3.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et Biophysica Acta-Bioenergetics

Pub Date : 2025-01-01 Epub Date: 2024-10-18 DOI: 10.1016/j.bbabio.2024.149520

Mariafrancesca Scalise , Raffaella Scanga , Lara Console , Michele Galluccio , Lorena Pochini , Cesare Indiveri

LAT1 (SLC7A5) catalyzes an antiport reaction of amino acids with specificity towards the essential ones. It is mainly expressed at the Blood Brain Barrier and placenta barriers, but it becomes over-expressed in virtually all human cancers even if originating from tissues with lower expression levels. The antiport reaction of LAT1 is crucial at the BBB since its inherited loss causes Autism Spectrum Disorder. We have investigated the possible molecular determinant of the antiport by site-directed mutagenesis, in vitro transport assay and computational analysis. Previous data indicated that mutation of K204 impairs, but does not knock-out LAT1 functionality. We have investigated the activity changes in the K204Q mutant by following the transport of [³H]-histidine, one of the major substrates, in proteoliposomes harbouring the WT or K204Q. In the mutant, the [³H]-histidine uptake and efflux are not more stimulated by the counter-substrate as they occur in the WT. Moreover, the mutation strongly decreases the substrate affinity and alters the pH dependence of K204Q. Molecular Dynamics analysis correlates well with the experimental data since it shows that substrate prematurely escapes the binding site. In addition, the K204Q shows a strongly increased mobility in those regions, transmembrane domains and random coils, involved in the transport cycle. The identified Lys residue could be responsible of the same phenomenon in those members of the SLC7 family, described as antiporters, in which it is conserved.

LAT1（SLC7A5）催化氨基酸的反转运反应，对必需氨基酸具有特异性。它主要在血脑屏障和胎盘屏障中表达，但在几乎所有人类癌症中都会过度表达，即使是来自表达水平较低的组织。由于 LAT1 的遗传性缺失会导致自闭症谱系障碍，因此它在血脑屏障中的反转运反应至关重要。我们通过定点突变、体外转运试验和计算分析研究了反转运的可能分子决定因素。之前的数据表明，K204 的突变会损害 LAT1 的功能，但不会导致其丧失。我们通过跟踪[3H]-组氨酸（主要底物之一）在含有 WT 或 K204Q 的蛋白脂质体中的转运情况，研究了 K204Q 突变体的活性变化。在突变体中，[3H]-组氨酸的摄取和流出并没有像在 WT 中那样受到反底物的刺激。此外，突变体强烈降低了底物亲和力，并改变了 K204Q 的 pH 依赖性。分子动力学分析与实验数据密切相关，因为它显示底物过早地脱离了结合位点。此外，K204Q 在参与运输循环的跨膜结构域和随机线圈等区域的移动性显著增加。在被称为反转运体的 SLC7 家族成员中，所发现的赖氨酸残基也可能是造成相同现象的原因，因为在这些成员中，赖氨酸残基是保守的。

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