Contact (Thousand Oaks (Ventura County, Calif.))最新文献

Pseudomonas syringae HopN1 Binds Plant VAP12 and a Rho-GTPase, Suggesting a Role in Membrane-Associated Processes. 丁香假单胞菌HopN1结合植物VAP12和Rho-GTPase，提示在膜相关过程中起作用。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-09-04 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251376890

Charlotte Brinkmann, Jennifer Bortlik, Frederik Börnke

{"title":"Pseudomonas syringae HopN1 Binds Plant VAP12 and a Rho-GTPase, Suggesting a Role in Membrane-Associated Processes.","authors":"Charlotte Brinkmann, Jennifer Bortlik, Frederik Börnke","doi":"10.1177/25152564251376890","DOIUrl":"10.1177/25152564251376890","url":null,"abstract":"Many Gram-negative bacterial pathogens deploy type III effector proteins (T3Es) to manipulate host cellular processes and suppress immune responses. Increasing evidence suggests that certain T3Es mimic eukaryotic FFAT (two phenylalanines in an acidic tract) motifs, enabling interaction with vesicle-associated membrane protein (VAMP)-associated proteins (VAPs). These interactions likely help pathogens target and exploit host membrane contact sites. However, the significance and distribution of FFAT mimicry across different bacterial pathogens remain poorly understood, which is crucial to uncovering its role in pathogenic strategies. In this study, we analyzed the T3E repertoire of the model plant pathogenic bacterium Pseudomonas syringae pv. tomato (Pst) DC3000 to identify potential FFAT motifs. Our preliminary data reveal that HopN1, a Pst T3E belonging to the YopT/AvrPphB family of cysteine proteases, contains at least one functional FFAT motif. Yeast two-hybrid and in planta co-immunoprecipitation assays confirmed that HopN1 interacts with plant VAP proteins. This interaction suggests that VAP binding may facilitate its localization to specific membrane compartments. Furthermore, HopN1 was shown to interact with a plant RHO-GTPase, hinting at a functional parallel to YopT in mammals. Our findings demonstrate that HopN1 interacts with VAP12 and a plant RHO-GTPase, suggesting a potential role in membrane-associated processes. However, whether HopN1 actively exploits VAP proteins for subcellular localization remains to be determined. While FFAT motif mimicry may contribute to effector targeting in plant-pathogenic bacteria, further studies are required to establish its functional significance in HopN1 virulence.","PeriodicalId":101304,"journal":{"name":"Contact (Thousand Oaks (Ventura County, Calif.))","volume":"8 ","pages":"25152564251376890"},"PeriodicalIF":0.0,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12411717/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145017042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

MCS Ultrastructural Analyses Using Electron Microscopy. 电子显微镜下MCS超微结构分析。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-09-01 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251372668

Atsuki Nara

引用次数: 0

Via Proteins and Lipids - Versatility of VAPs at Dynamic Membrane Contact Sites. 通过蛋白质和脂质- VAPs在动态膜接触部位的多功能性。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-08-26 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251372673

Dan Zhang

引用次数: 0

Membrane Contact Sites in Proteostasis and ER Stress Response. 蛋白静止和内质网应激反应中的膜接触位点。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-07-28 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251363050

Febe Vermue, Aysegul Sapmaz, Ilana Berlin

{"title":"Membrane Contact Sites in Proteostasis and ER Stress Response.","authors":"Febe Vermue, Aysegul Sapmaz, Ilana Berlin","doi":"10.1177/25152564251363050","DOIUrl":"10.1177/25152564251363050","url":null,"abstract":"Execution of all cellular functions depends on a healthy proteome, whose maintenance requires multimodal oversight. Roughly a third of human proteins reside in membranes and thus present unique topological challenges with respect to biogenesis and degradation. To meet these challenges, eukaryotes have evolved organellar pathways of protein folding and quality control. Most transmembrane proteins originate in the endoplasmic reticulum (ER), where they are subject to surveillance and, if necessary, removal through either ER-associated proteasomal degradation (cytosolic pathway) or selective autophagy (ER-phagy; organellar pathway). In the latter case, ER cargoes are shuttled to (endo)lysosomes - the same organelles that degrade cell surface molecules via endocytosis. Here, we provide an overview of dynamic coordination between the ER and endolysosomes, with a focus on their engagement in specialized physical interfaces termed membrane contact sites (MCSs). We cover how cross-compartmental integration through MCSs allows biosynthetic and proteolytic organelles to fine-tune each other's membrane composition, organization, and dynamics and facilitates recovery from proteotoxic stress. Along the way, we highlight recent developments and open questions at the crossroads between organelle biology and protein quality control and cast them against the backdrop of factor-specific diseases associated with perturbed membrane homeostasis.","PeriodicalId":101304,"journal":{"name":"Contact (Thousand Oaks (Ventura County, Calif.))","volume":"8 ","pages":"25152564251363050"},"PeriodicalIF":0.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12304649/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144746724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Endoplasmic reticulum-Mitochondria Coupling in Alzheimer's Disease. 阿尔茨海默病的内质网-线粒体偶联。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-07-17 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251330069

Michela Rossini, Tânia Fernandes, Irene D'Arsiè, Riccardo Filadi

引用次数: 0

Identification of ER:Melanosome Membrane Contact Sites in the Retinal Pigment Epithelium. 视网膜色素上皮内黑素小体膜接触部位的鉴定。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-06-02 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251340949

T Burgoyne, D Doncheva, E R Eden

{"title":"Identification of ER:Melanosome Membrane Contact Sites in the Retinal Pigment Epithelium.","authors":"T Burgoyne, D Doncheva, E R Eden","doi":"10.1177/25152564251340949","DOIUrl":"10.1177/25152564251340949","url":null,"abstract":"The retinal pigment epithelium (RPE) forms a monolayer of cells at the blood:retina interface that plays important roles for photoreceptor renewal and function and is central to retinal health. RPE pigment is provided by melanin-containing melanosomes which offer protection against light and oxidative stress. Melanosome migration into the apical processes of the RPE following light onset is thought to contribute to preventing retinal degeneration with age, though the mechanism is not yet clear. Melanosomes are transported along microtubules to the apical surface where they are transferred to actin filaments within the apical processes. Melanosomes are lysosome-related organelles derived from endosomes and endosome transport along microtubules is heavily influenced by the endoplasmic reticulum (ER) through ER:endosome contact sites. Here we describe extensive connection between the ER and melanosomes in the RPE. We further show, in skin melanocytes, that the ER forms contact sites with all stages of melanosome maturation, but ER contact is reduced as melanosomes mature. Finally, we identify tripartite contact sites between the ER, melanosomes and mitochondria in both RPE tissue and cellular models, suggesting that the ER may influence melanosome biogenesis, maturation and interaction with mitochondria.","PeriodicalId":101304,"journal":{"name":"Contact (Thousand Oaks (Ventura County, Calif.))","volume":"8 ","pages":"25152564251340949"},"PeriodicalIF":0.0,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12130655/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144218095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Plant NETWORKED and VAP27 Proteins Work in Complexes to Regulate Membrane-Based Functions. 植物网络蛋白和VAP27蛋白通过复合物调节膜基功能

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-05-27 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251342533

Patrick J Duckney, Pengwei Wang, Patrick J Hussey

{"title":"Plant NETWORKED and VAP27 Proteins Work in Complexes to Regulate Membrane-Based Functions.","authors":"Patrick J Duckney, Pengwei Wang, Patrick J Hussey","doi":"10.1177/25152564251342533","DOIUrl":"10.1177/25152564251342533","url":null,"abstract":"Eukaryotic cells are subdivided into specialised organelle compartments, each with unique physiological environments and functions. Interaction and cross-talk between organelles is inherent to Eukaryotic life, and each organelle is physically interconnected to their surrounding subcellular components including the cytoskeleton and adjacent membrane compartments. In animals and yeast, the mechanisms of organelle interaction have been well characterised and are known to have fundamental importance to life. In contrast, we are only beginning to understand the mechanisms and functions of such interactions in plants. The discovery and ongoing characterisation of the NETWORKED (NET) protein family of plant actin-membrane adaptors has greatly advanced our understanding of the mechanisms of organelle-cytoskeletal interaction. Furthermore, unfolding investigation into the NET proteins has revealed their binding partner, VAMP-ASSOCIATED PROTEIN-27 (VAP27), to be a regulator of organelle tethering and interaction with previously unknown, specialised roles in plants. Research on NET and VAP27 proteins has rapidly increased our knowledge of the mechanisms regulating membrane interaction in plants, their functions in regulating cell structure and organisation, as well as their importance to plant growth, development and stress-response. Here, we discuss the discovery and characterisation of the NET and VAP27 proteins, their regulation of organelle interaction and their functions in plants.","PeriodicalId":101304,"journal":{"name":"Contact (Thousand Oaks (Ventura County, Calif.))","volume":"8 ","pages":"25152564251342533"},"PeriodicalIF":0.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12127668/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144210655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Artificial ER-Mitochondrion Tethering Restores Erg6 Localization and Lipid Droplet Formation in Hansenula polymorpha Δpex23 and Δpex29 Cells. 人工er -线粒体系扎恢复多形海参Δpex23和Δpex29细胞Erg6定位和脂滴形成

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-04-18 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251336908

Haiqiong Chen, Rinse de Boer, David C Lamb, Steven L Kelly, Ida J van der Klei

{"title":"Artificial ER-Mitochondrion Tethering Restores Erg6 Localization and Lipid Droplet Formation in Hansenula polymorpha Δpex23 and Δpex29 Cells.","authors":"Haiqiong Chen, Rinse de Boer, David C Lamb, Steven L Kelly, Ida J van der Klei","doi":"10.1177/25152564251336908","DOIUrl":"https://doi.org/10.1177/25152564251336908","url":null,"abstract":"Pex23 proteins are a family of fungal endoplasmic reticulum proteins. Hansenula polymorpha contains four members, two of which, Pex24 and Pex32, function in endoplasmic reticulum-peroxisome membrane contact sites. In the absence of the other two members, Pex23 and Pex29, mitochondria are fragmented and lipid droplet numbers are reduced. We here show that in Δpex23 and Δpex29 cells an increased portion of the lipid droplet protein Erg6 (C24-methyltransferase), an enzyme involved in ergosterol biosynthesis, localizes to mitochondria. Erg6 relocalization and the reduction in lipid droplet numbers are suppressed by an artificial endoplasmic reticulum-mitochondrion tether protein. Sterol measurements showed that the presence of Erg6 at mitochondria did not cause major changes in the overall sterol composition. Our findings suggest that Pex23 and Pex29 play a role in endoplasmic reticulum-mitochondrion contact sites which prevent mitochondrial mislocalization of Erg6.","PeriodicalId":101304,"journal":{"name":"Contact (Thousand Oaks (Ventura County, Calif.))","volume":"8 ","pages":"25152564251336908"},"PeriodicalIF":0.0,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12033454/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144056738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Profiling the LAM Family of Contact Site Tethers Provides Insights into Their Regulation and Function. 分析LAM家族的接触点系绳提供了对其调节和功能的见解。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-04-17 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251321770

Emma J Fenech, Meital Kupervaser, Angela Boshnakovska, Shani Ravid, Inês Gomes Castro, Yeynit Asraf, Sylvie Callegari, Christof Lenz, Henning Urlaub, Peter Rehling, Maya Schuldiner

{"title":"Profiling the LAM Family of Contact Site Tethers Provides Insights into Their Regulation and Function.","authors":"Emma J Fenech, Meital Kupervaser, Angela Boshnakovska, Shani Ravid, Inês Gomes Castro, Yeynit Asraf, Sylvie Callegari, Christof Lenz, Henning Urlaub, Peter Rehling, Maya Schuldiner","doi":"10.1177/25152564251321770","DOIUrl":"https://doi.org/10.1177/25152564251321770","url":null,"abstract":"Membrane contact sites are molecular bridges between organelles that are sustained by tethering proteins and enable organelle communication. The endoplasmic reticulum (ER) membrane harbors many distinct families of tether proteins that enable the formation of contacts with all other organelles. One such example is the LAM (Lipid transfer protein Anchored at Membrane contact sites) family in yeast, which is composed of six members, each containing a putative lipid binding and transfer domain and an ER-embedded transmembrane segment. The family is divided into three homologous pairs each unique in their molecular architecture and localization to different ER subdomains. However, what determines the distinct localization of the different LAMs and which specific roles they carry out in each contact are still open questions. To address these, we utilized a labeling approach to profile the proximal protein landscape of the entire family. Focusing on unique, candidate interactors we could support that Lam5 resides at the ER-mitochondria contact site and demonstrate a role for it in sustaining mitochondrial activity. Capturing shared, putative interactors of multiple LAMs, we show how the Lam1/3 and Lam2/4 paralogous pairs could be associated specifically with the plasma membrane. Overall, our work provides new insights into the regulation and function of the LAM family members. More globally it demonstrates how proximity labeling can help identify the shared or unique functions of paralogous proteins.","PeriodicalId":101304,"journal":{"name":"Contact (Thousand Oaks (Ventura County, Calif.))","volume":"8 ","pages":"25152564251321770"},"PeriodicalIF":0.0,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12033502/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144051866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mitochondria-Plasma Membrane Contact Sites: Emerging Regulators of Mitochondrial Form and Function. 线粒体-质膜接触位点：线粒体形式和功能的新兴调节因子。

Contact (Thousand Oaks (Ventura County, Calif.)) Pub Date : 2025-04-13 eCollection Date: 2025-01-01 DOI: 10.1177/25152564251332141

Jason C Casler, Matilde V Neto, Thomas Burgoyne, Laura L Lackner

引用次数: 0