Journal of Biological Chemistry最新文献_第8页

Structural and Enzymatic Plasticity of SIRT6 Deacylase Activity. SIRT6脱乙酰酶活性的结构和酶可塑性。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108446

Zhipeng A Wang, Jonathan Markert, Samual D Whedon, Maheeshi Yapa Abeywardana, Xinlei Sheng, Eunju Nam, Kwangwoon Lee, Maggie Chen, Amanda Waterbury, Yingming Zhao, Lucas Farnung, Philip A Cole

{"title":"Structural and Enzymatic Plasticity of SIRT6 Deacylase Activity.","authors":"Zhipeng A Wang, Jonathan Markert, Samual D Whedon, Maheeshi Yapa Abeywardana, Xinlei Sheng, Eunju Nam, Kwangwoon Lee, Maggie Chen, Amanda Waterbury, Yingming Zhao, Lucas Farnung, Philip A Cole","doi":"10.1016/j.jbc.2025.108446","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108446","url":null,"abstract":"Sirtuin 6 (SIRT6) is an NAD-dependent protein deacylase that targets lysine residues in histones in the cell nucleus, where it helps maintain genome stability and links metabolism to epigenetic control. Dysregulation of SIRT6 is believed to be associated with aging and cancer, making it of pharmacological interest. In this study, we use cryogenic electron microscopy (cryo-EM) and enzymology to explore SIRT6 preference and adaptability towards different nucleosomal substrates. We have visualized a trapped complex of SIRT6 in the process of deacylating H3K27, demonstrating how SIRT6 undergoes conformational changes to remove differently positioned histone marks. Additional biochemical studies further reveal SIRT6's plasticity, which accommodates various metabolism-linked modifications such as lysine lactylation and β-hydroxybutyrylation. To further understand the basis for substrate selectivity of SIRT6, we explore the effects of an established G60A enzyme mutation, proximal H3 modifications, and small molecule modulators. These findings highlight SIRT6's versatility and provide key mechanistic insights into its molecular recognition.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108446"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identification of the phosphatase essential for riboflavin biosynthesis in Aquifex aeolicus. 水蛭核黄素合成必需磷酸酶的鉴定。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108443

Zoe A Hoffpauir, Audrey L Lamb

{"title":"Identification of the phosphatase essential for riboflavin biosynthesis in Aquifex aeolicus.","authors":"Zoe A Hoffpauir, Audrey L Lamb","doi":"10.1016/j.jbc.2025.108443","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108443","url":null,"abstract":"The riboflavin biosynthetic pathway uses dedicated enzymes that function exclusively for riboflavin production. Indeed, the pathway is fully annotated, with the exception of an unknown phosphatase that catalyzes the dephosphorylation of 5-amino-6-ribitylamino-pyrimidinedione 5'-phosphate (ARAPDP) to generate 5-amino-6-ribitylamino-pyrimidinedione (ARAPD), which is the substrate for the penultimate enzyme of the pathway, lumazine synthase. Whereas non-specific phosphatases from the haloacid dehalogenase (HAD) superfamily capable of catalyzing the dephosphorylation of ARAPDP have been reported for Bacillus subtilis, Escherichia coli, and Arabadopsis thaliana, we hypothesized that a specific phosphatase may carry out this reaction. Using an anaerobic activity-based screen, two phosphatases from Aquifex aeolicus were identified that dephosphorylate ARAPDP, but only one reconstitutes riboflavin production in a one-pot experiment with the other four enzymes of riboflavin biosynthesis. The first enzyme, annotated as an inositol monophosphatase (IMP), is non-specific, and indiscriminately dephosphorylates ARAPDP along with ribulose 5-phosphate and NADPH, two required substrates of riboflavin biosynthesis. The second enzyme, a histidine family phosphatase (HFP), only dephosphorylates ARAPDP in the one-pot experiment thus facilitating riboflavin formation. The structures of both enzymes were determined by x-ray crystallography to reveal the vastly different folds capable of performing the ARAPDP dephosphorylation chemistry. This work has impact both for microbial fermentation production of riboflavin and for antimicrobial drug design.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108443"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Complex G-protein signaling of the adhesion GPCR, ADGRA3. 粘附GPCR的复合g蛋白信号传导，ADGRA3。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-22 DOI: 10.1016/j.jbc.2025.108441

Sofie M Bagger, Hannes Schihada, Anna L S Walser, Anna Katarzyna Drzazga, Lukas Grätz, Tiago Palmisano, Christina K Kuhn, Maša Mavri, Ann-Sophie Mølleskov-Jensen, Gregory G Tall, Torsten Schöneberg, Signe J Mathiasen, Jonathan A Javitch, Gunnar Schulte, Katja Spiess, Mette M Rosenkilde

{"title":"Complex G-protein signaling of the adhesion GPCR, ADGRA3.","authors":"Sofie M Bagger, Hannes Schihada, Anna L S Walser, Anna Katarzyna Drzazga, Lukas Grätz, Tiago Palmisano, Christina K Kuhn, Maša Mavri, Ann-Sophie Mølleskov-Jensen, Gregory G Tall, Torsten Schöneberg, Signe J Mathiasen, Jonathan A Javitch, Gunnar Schulte, Katja Spiess, Mette M Rosenkilde","doi":"10.1016/j.jbc.2025.108441","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108441","url":null,"abstract":"ADGRA3 (GPR125) is an orphan adhesion G protein-coupled receptor (aGPCR) that plays a role in planar cell polarity (PCP), primarily through recruitment of the signaling components Dishevelled (DVL) during vertebrate gastrulation, and Discs large homolog 1 (Dlg1), which is implicated in cancer. Limited knowledge exists of the signaling capacity in the canonical GPCR pathways of ADGRA3. Here, we employed a series of human cell line-based signaling assays to gain insight into the heterotrimeric G protein-mediated signaling of ADGRA3. We based the design of ADGRA3 constructs on analyses of transcript variants in publicly available human liver and brain RNA-seq datasets. As cleavage in the GPCR autoproteolysis site (GPS) is a hallmark for many aGPCRs, we generated a truncated ADGRA3 (C-terminal fragment, CTF) corresponding to a potential cleavage at the GPS. We found low-level activation of Gi and Gs by ADGRA3 and slightly more by its CTF. As the N terminus of the CTF constitutes a class-defined tethered agonist known as the stachel peptide, we removed the initial three amino acids of the CTF. This resulted in abrogated G protein-mediated signaling, as observed for other aGPCRs. Due to the central role of ADGRA3 in PCP signaling through DVL recruitment, we investigated the G-protein signaling in absence of DVL1-3 and found it sustained. No transcriptional activation was observed downstream of β-catenin in an assay reporting T-cell factor/lymphoid enhancer factor (TCF/LEF)-mediated transcriptional activity. Collectively, this establishes a classical G protein-mediated signaling for ADGRA3 in addition to its association with components of non-canonical Wnt-signaling pathways.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108441"},"PeriodicalIF":4.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spt6-Spn1 interaction is required for RNA Polymerase II association and precise nucleosome positioning along transcribed genes. Spt6-Spn1相互作用是RNA聚合酶II结合和沿转录基因精确定位核小体所必需的。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-22 DOI: 10.1016/j.jbc.2025.108436

Boning Chen, Raghuvar Dronamraju, Whitney R Smith-Kinnaman, Sarah A Peck Justice, Austin J Hepperla, Heather K MacAlpine, Jeremy M Simon, Amber L Mosley, David M MacAlpine, Brian D Strahl

{"title":"Spt6-Spn1 interaction is required for RNA Polymerase II association and precise nucleosome positioning along transcribed genes.","authors":"Boning Chen, Raghuvar Dronamraju, Whitney R Smith-Kinnaman, Sarah A Peck Justice, Austin J Hepperla, Heather K MacAlpine, Jeremy M Simon, Amber L Mosley, David M MacAlpine, Brian D Strahl","doi":"10.1016/j.jbc.2025.108436","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108436","url":null,"abstract":"Spt6-Spn1 is an essential histone chaperone complex that associates with RNA Polymerase II (RNAPII) and reassembles nucleosomes during gene transcription. While the interaction between Spt6 and Spn1 is important for its histone deposition and transcription functions, a precise mechanistic understanding is still limited. Here, using temperature sensitive alleles of spt6 and spn1 that disrupt their interaction in yeast, we show that Spt6-Spn1 association is important for its stable interaction with the elongating RNAPII complex and nucleosomes. Using micrococcal nuclease (MNase)-based chromatin occupancy profiling, we further find that Spt6-Spn1 interaction is required to maintain a preferred nucleosome positioning at actively transcribed genes; in the absence of Spt6-Spn1 interaction, we observe a return to replication-dependent phasing. In addition to positioning defects, Spt6-Spn1 disrupting mutants also resulted in an overall shift of nucleosomes towards the 5' end of genes that was correlated with decreased RNAPII levels. As loss of Spt6-Spn1 association results in cryptic transcription at a subset of genes, we examined these genes for their nucleosome profiles. These findings revealed that the chromatin organization at these loci is similar to other active genes, thus underscoring the critical role of DNA sequence in mediating cryptic transcription when nucleosome positioning is altered. Taken together, these findings reveal Spt6-Spn1 interaction is key to its association with elongating RNAPII and for its ability to precisely organize nucleosomes across transcription units.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108436"},"PeriodicalIF":4.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Melatonin-mediated cGAS-STING signal in senescent macrophages promote TNBC chemotherapy resistance and drive the SASP. 褪黑素介导的衰老巨噬细胞cGAS-STING信号促进TNBC化疗耐药并驱动SASP。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-22 DOI: 10.1016/j.jbc.2025.108438

Xiaoqiang Zhang, Minyu Zhuang, Hongfei Zhang, Yanhui Zhu, Junzhe Yang, Xian Wu, Xiafei Yu, Jing Tao, Xiaoan Liu

{"title":"Melatonin-mediated cGAS-STING signal in senescent macrophages promote TNBC chemotherapy resistance and drive the SASP.","authors":"Xiaoqiang Zhang, Minyu Zhuang, Hongfei Zhang, Yanhui Zhu, Junzhe Yang, Xian Wu, Xiafei Yu, Jing Tao, Xiaoan Liu","doi":"10.1016/j.jbc.2025.108438","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108438","url":null,"abstract":"The build-up of senescent cells in tissues is a key indicator of aging, associated with negative prognosis and therapy resistance. Despite immune dysfunction related to aging, also known as immunosenescence, is recognized as a factor in this process, the exact mechanisms are still unclear. In this study, we reported that melatonin deficiency accelerated macrophage senescence in triple-negative breast cancer (TNBC), whereas, melatonin could defend macrophages against senescence through the Nfatc1-Trim26-cgas-Sting pathway. Mechanistically, melatonin enhanced the nuclear translocation of Nfatc1 and elevated Trim26 transcription levels. Trim26, functioning as an E3 ligase, ubiquitinates cgas, thereby inhibiting the activation of the cgas-Sing pathway and consequently preventing cell senescence. Conversely, melatonin deficiency induced cgas-Sting pathway activation to promote macrophage aging. Our results show that melatonin inhibited macrophage senescence and improved chemotherapy responsiveness, with further enhancement when combined with the cgas inhibitor (G150). Overall, our findings indicated that melatonin protects macrophages from immunosenescence, suggesting its therapeutic potential for enhancing chemotherapy response.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108438"},"PeriodicalIF":4.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mapping the structural heterogeneity of Pup ligase PafA using H/D exchange mass spectrometry. 利用H/D交换质谱法绘制Pup连接酶paa的结构异质性。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-21 DOI: 10.1016/j.jbc.2025.108437

Alicia Plourde, Jacquelyn C Ogata-Bean, Siavash Vahidi

{"title":"Mapping the structural heterogeneity of Pup ligase PafA using H/D exchange mass spectrometry.","authors":"Alicia Plourde, Jacquelyn C Ogata-Bean, Siavash Vahidi","doi":"10.1016/j.jbc.2025.108437","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108437","url":null,"abstract":"The Pup-proteasome system (PPS) is a unique bacterial proteolytic pathway found in some bacterial species, including in Mycobacterium tuberculosis, that plays a vital role in maintaining proteome integrity and survival during infection. Pupylation is the process of tagging substrates with Pup for degradation and is catalyzed by PafA, the sole Pup ligase in bacteria. However, how PafA interacts with diverse targets and its oligomeric state remain poorly understood. Although X-ray crystal structures have characterized PafA as a domain-swapped dimer, it is widely regarded as functionally active in its monomeric form. It remains to be established whether PafA dimerizes in solution, and how dimerization influences its function. In this study, we employed hydrogen-deuterium exchange mass spectrometry (HDX-MS) alongside complementary biophysical techniques to explore the oligomeric states and conformational dynamics of PafA. We show that recombinantly-produced PafA exists in a monomeric and a domain-swapped dimeric state in solution. Although nucleotide binding stabilizes PafAdimer, it primarily adopts a catalytically inactive conformation. Our HDX-MS highlighted regions throughout the N- and C-terminal domains that facilitate the PafA dimerization process. HDX-MS also revealed nucleotide binding induces global conformational changes on PafAmonomer, underscoring the structural plasticity of this promiscuous enzyme. Our findings enhance our understanding of the structural and conformational heterogeneity of PafA and demonstrate how nucleotide binding and dimerization may influence its function.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108437"},"PeriodicalIF":4.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Pseudomonas aeruginosa PhuS proximal ligand His-209 triggers a conformational switch in function from DNA binding to heme transfer. 铜绿假单胞菌PhuS近端配体His-209触发从DNA结合到血红素转移的功能构象开关。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-21 DOI: 10.1016/j.jbc.2025.108440

Nicholas Montes, Tyree Wilson, Samuel A Krug, Susana Mouriño, Maureen A Kane, Daniel Deredge, Angela Wilks

{"title":"The Pseudomonas aeruginosa PhuS proximal ligand His-209 triggers a conformational switch in function from DNA binding to heme transfer.","authors":"Nicholas Montes, Tyree Wilson, Samuel A Krug, Susana Mouriño, Maureen A Kane, Daniel Deredge, Angela Wilks","doi":"10.1016/j.jbc.2025.108440","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108440","url":null,"abstract":"Pseudomonas aeruginosa can acquire iron from heme via the heme assimilation system (Has) and Pseudomonas heme uptake (Phu) systems. Heme uptake is regulated at the metabolic level by the cytoplasmic protein PhuS, that controls heme flux through a heme oxygenase HemO, releasing iron and biliverdin IXβ and IXδ. We have shown PhuS regulates extracellular heme flux, and in its apo-form transcriptionally regulates the iron and heme-dependent sRNAs PrrF/PrrH. This mutual exclusivity of function is driven by conformational rearrangement of PhuS on heme binding. Herein we show through a combination of EMSA and fluorescence anisotropy that mutation of the His-209 proximal ligand allows both apo- and holo-PhuS H209A to bind to the prrF1 promoter with significantly lower affinity when compared to PAO1 WT. HDX-MS revealed the apo- and holo-PhuS H209A structures are closer to each other than their WT counterparts and sample a conformational landscape between the apo- and holo-PhuS WT conformations, that is neither optimal for heme transfer nor DNA-binding. Furthermore, qPCR and Western blot analysis of the phuSH209A allelic strain compared to PAO1 WT revealed an uncoupling of the PhuS-HemO dependent regulation of heme flux into the cell that abrogates the heme dependent regulation of the PrrF/PrrH sRNAs. The data supports a model where heme coordination through His-209 drives the conformational switch that determines mutual exclusivity in function of apo- and holo-PhuS. This dual function of PhuS is central to integrating extracellular heme utilization into the PrrF/PrrH sRNA regulatory network critical for P. aeruginosa adaptation within the host.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108440"},"PeriodicalIF":4.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PKM2 regulates osteoclastogenesis by affecting osteoclast precursor cell fusion via downregulation of OC-STAMP and DC-STAMP. PKM2通过下调OC-STAMP和DC-STAMP来影响破骨细胞前体细胞融合，从而调控破骨细胞的发生。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-21 DOI: 10.1016/j.jbc.2025.108439

Cong Cai, Jiawei Jiang, Song Li, Chenghao Gao, Hongxu Pu, Libo Zhao, Jun Xiao

{"title":"PKM2 regulates osteoclastogenesis by affecting osteoclast precursor cell fusion via downregulation of OC-STAMP and DC-STAMP.","authors":"Cong Cai, Jiawei Jiang, Song Li, Chenghao Gao, Hongxu Pu, Libo Zhao, Jun Xiao","doi":"10.1016/j.jbc.2025.108439","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108439","url":null,"abstract":"Osteoporosis is a common bone disease that has become a serious public health problem with the aging of population. Osteoclasts are the only cells in body that can resorb bone, whose dysfunction is closely related to osteoporosis. Pyruvate kinase M2 (PKM2) is one of the essential rate-limiting enzymes in the process of glycolysis. This study aimed to elucidate the role of PKM2 in osteoclastogenesis and bone resorption. Bone marrow-derived macrophages (BMMs) were transfected with adenovirus to knock down the expression of PKM2 gene or treated with the PKM2 activators DASA-58 and TEPP-46. Osteoclast formation was detected by TRAP staining, osteoclast-specific gene and protein expression was detected by RT-qPCR and Western blotting, and the effect of DASA-58 on osteoclast gene expression at the transcriptional level was examined by RNA-seq. The results showed that knockdown of PKM2 by adenoviral transfection or treatment with PKM2 activators DASA-58 and TEPP-46 inhibited osteoclast differentiation and suppressed the expression of osteoclast-associated genes in BMMs. Furthermore, PKM2 activators DASA-58 and TEPP-46 could inhibit several signaling pathways in osteoclasts; knockdown of PKM2 or treatment with PKM2 activators DASA-58 and TEPP-46 both affected osteoclast precursor cell fusion by inhibiting the expression of osteoclast stimulatory transmembrane protein (OC-STAMP) and dendritic cell-specific transmembrane protein (DC-STAMP). Therefore, PKM2 is closely related to osteoclast differentiation and formation, and the development of new therapeutic strategies targeting the PKM2 gene in osteoclasts may be feasible for the prevention and treatment of osteoporosis.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108439"},"PeriodicalIF":4.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

H₂S remodels mitochondrial ultrastructure and destabilizes respiratory supercomplexes. H2S重塑线粒体超微结构，破坏呼吸超复合体的稳定。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-20 DOI: 10.1016/j.jbc.2025.108433

David A Hanna, Brandon Chen, Yatrik M Shah, Oleh Khalimonchuk, Brian Cunniff, Ruma Banerjee

引用次数: 0

Structure and membrane interactions of Arabidopsis thaliana DGD2, a glycosyltransferase in the chloroplast membrane. 拟南芥叶绿体膜糖基转移酶DGD2的结构和膜相互作用。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-20 DOI: 10.1016/j.jbc.2025.108431

Emma Scaletti Hutchinson, Markel Martínez-Carranza, Biao Fu, Lena Mäler, Pål Stenmark

{"title":"Structure and membrane interactions of Arabidopsis thaliana DGD2, a glycosyltransferase in the chloroplast membrane.","authors":"Emma Scaletti Hutchinson, Markel Martínez-Carranza, Biao Fu, Lena Mäler, Pål Stenmark","doi":"10.1016/j.jbc.2025.108431","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108431","url":null,"abstract":"Galactolipids are characteristic lipids of the photosynthesis membranes of higher plants and cyanobacteria. Due to their close relationship to the stability of the photosystem protein complexes, the biogenesis of galactolipids has been intensively studied on the genetic and molecular levels. There are two major types of galactolipids in chloroplastic membranes: monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG). Under phosphate-limiting conditions, the amount of DGDG increases dramatically to allow for phosphate salvage from phospholipids. In Arabidopsis thaliana, the membrane-associated glycosyltransferase Digalactosyldiacylglycerol synthase 2 (atDGD2) is highly responsive to phosphate starvation and is significantly upregulated during such conditions. The lipid galactosylation reactions are also fundamentally interesting as they require a catalyst that is capable of bringing a hydrophilic and lipophilic substrate together at the solution-membrane phase border. Here we present the X-ray crystal structure of atDGD2, which is the first reported DGDG synthase structure. AtDGD2 is most structurally similar to functionally unrelated GT-B enzymes. Interestingly, in spite of significant donor substrate binding differences we identified four amino acids (Gly22, His151, Lys243 and Glu321, atDGD2 numbering) which were entirely conserved between the structurally similar enzymes. We also investigated the membrane interaction kinetics and membrane anchoring mechanism of atDGD2. This demonstrated that atDGD2 is membrane-bound, but also showed that membrane binding is highly dynamic. Furthermore, our structural information in context of previous biophysical studies highlights regions of the enzyme exhibiting a high degree of structural plasticity, which we propose to be important for allowing atDGD2 to quickly adapt its activity based on the membrane lipid environment.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108431"},"PeriodicalIF":4.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0