TrafficPub Date : 2022-04-24DOI: 10.1111/tra.12840
A. Bonhoure, L. Henry, C. Bich, L. Blanc, Blanche Bergeret, M. Bousquet, O. Coux, P. Stoebner, M. Vidal
{"title":"Extracellular 20S proteasome secreted via microvesicles can degrade poorly folded proteins and inhibit Galectin‐3 agglutination activity","authors":"A. Bonhoure, L. Henry, C. Bich, L. Blanc, Blanche Bergeret, M. Bousquet, O. Coux, P. Stoebner, M. Vidal","doi":"10.1111/tra.12840","DOIUrl":"https://doi.org/10.1111/tra.12840","url":null,"abstract":"Proteasomes are major non‐lysosomal proteolytic complexes localized in the cytoplasm and in the nucleus of eukaryotic cells. Strikingly, high levels of extracellular proteasome have also been evidenced in the plasma (p‐proteasome) of patients with specific diseases. Here, we examined the process by which proteasomes are secreted, as well as their structural and functional features once in the extracellular space. We demonstrate that assembled 20S core particles are secreted by cells within microvesicles budding from the plasma membrane. Part of the extracellular proteasome pool is also free of membranes in the supernatant of cultured cells, and likely originates from microvesicles leakage. We further demonstrate that this free proteasome released by cells (cc‐proteasome for cell culture proteasome) possesses latent proteolytic activity and can degrade various extracellular proteins. Both standard (no immune‐subunits) and intermediate (containing some immune‐subunits) forms of 20S are observed. Moreover, we show that galectin‐3, which displays a highly disordered N‐terminal region, is efficiently cleaved by purified cc‐proteasome, without SDS activation, likely after its binding to PSMA3 (α7) subunit through its intrinsically disordered region. As a consequence, galectin‐3 is unable to induce red blood cells agglutination when preincubated with cc‐proteasome. These results highlight potential novel physio‐ and pathologic functions for the extracellular proteasome.","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"174 1","pages":"287 - 304"},"PeriodicalIF":4.5,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73191740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TrafficPub Date : 2022-04-22DOI: 10.1111/tra.12844
Tiantian Qian, Chenlu Li, Furong Liu, K. Xu, Chun Wan, Yinghui Liu, Haijia Yu
{"title":"Arabidopsis synaptotagmin 1 mediates lipid transport in a lipid composition‐dependent manner","authors":"Tiantian Qian, Chenlu Li, Furong Liu, K. Xu, Chun Wan, Yinghui Liu, Haijia Yu","doi":"10.1111/tra.12844","DOIUrl":"https://doi.org/10.1111/tra.12844","url":null,"abstract":"The endoplasmic reticulum (ER)‐plasma membrane (PM) contact sites (EPCSs) are structurally conserved in eukaryotes. The Arabidopsis ER‐anchored synaptotagmin 1 (SYT1), enriched in EPCSs, plays a critical role in plant abiotic stress tolerance. It has become clear that SYT1 interacts with PM to mediate ER‐PM connectivity. However, whether SYT1 performs additional functions at EPCSs remains unknown. Here, we report that SYT1 efficiently transfers phospholipids between membranes. The lipid transfer activity of SYT1 is highly dependent on phosphatidylinositol 4,5‐bisphosphate [PI(4,5)P2], a signal lipid accumulated at the PM under abiotic stress. Mechanically, while SYT1 transfers lipids fundamentally through the synaptotagmin‐like mitochondrial‐lipid‐binding protein (SMP) domain, the efficient lipid transport requires the C2A domain‐mediated membrane tethering. Interestingly, we observed that Ca2+ could stimulate SYT1‐mediated lipid transport. In addition to PI(4,5)P2, the Ca2+ activation requires the phosphatidylserine, another negatively charged lipid on the opposed membrane. Together, our studies identified Arabidopsis SYT1 as a lipid transfer protein at EPCSs and demonstrated that it takes conserved as well as divergent mechanisms with other extend‐synaptotagmins. The critical role of lipid composition and Ca2+ reveals that SYT1‐mediated lipid transport is highly regulated by signals in response to abiotic stresses.","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"30 1","pages":"346 - 356"},"PeriodicalIF":4.5,"publicationDate":"2022-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90737497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TrafficPub Date : 2022-04-12DOI: 10.1111/tra.12842
A. Ciesielska, Marta Krawczy, H. Sas-Nowosielska, A. Hromada-Judycka, K. Kwiatkowska
{"title":"CD14 recycling modulates LPS‐induced inflammatory responses of murine macrophages","authors":"A. Ciesielska, Marta Krawczy, H. Sas-Nowosielska, A. Hromada-Judycka, K. Kwiatkowska","doi":"10.1111/tra.12842","DOIUrl":"https://doi.org/10.1111/tra.12842","url":null,"abstract":"TLR4 is activated by the bacterial endotoxin lipopolysaccharide (LPS) and triggers two proinflammatory signaling cascades: a MyD88‐dependent one in the plasma membrane, and the following TRIF‐dependent one in endosomes. An inadequate inflammatory reaction can be detrimental for the organism by leading to sepsis. Therefore, novel approaches to therapeutic modulation of TLR4 signaling are being sought after. The TLR4 activity is tightly connected with the presence of CD14, a GPI‐anchored protein that transfers LPS monomers to the receptor and controls its endocytosis. In this study we focused on CD14 trafficking as a still poorly understood factor affecting TLR4 activity. Two independent assays were used to show that after endocytosis CD14 can recycle back to the plasma membrane in both unstimulated and stimulated cells. This route of CD14 trafficking can be controlled by sorting nexins (SNX) 1, 2 and 6, and is important for maintaining the surface level and the total level of CD14, but can also affect the amount of TLR4. Silencing of these SNXs attenuated especially the CD14‐dependent endosomal signaling of TLR4, making them a new target for therapeutic regulation of the inflammatory response of macrophages to LPS.","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"62 1","pages":"310 - 330"},"PeriodicalIF":4.5,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80666875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TrafficPub Date : 2022-04-01Epub Date: 2022-03-01DOI: 10.1111/tra.12834
Elisabeth Richardson, Joel B Dacks
{"title":"Distribution of membrane trafficking system components across ciliate diversity highlights heterogenous organelle-associated machinery.","authors":"Elisabeth Richardson, Joel B Dacks","doi":"10.1111/tra.12834","DOIUrl":"https://doi.org/10.1111/tra.12834","url":null,"abstract":"<p><p>The ciliate phylum is a group of protists noted for their unusual membrane trafficking system and apparent environmental ubiquity; as highly successful microbial predators, they are found in all manner of environments and the ability for specific species to adapt to extremely challenging conditions makes them valued as bioindicators. Ciliates have also been used for many years as cell biological models because of their large cell size and ease of culturing, and for many fundamental cell structures, particularly membrane-bound organelles, ciliates were some of the earliest organisms in which these were observed via microscopy. In this study, we carried out a comparative genomic survey of selected membrane trafficking proteins in a pan-ciliate transcriptome and genome dataset. We observed considerable loss of membrane trafficking system (MTS) proteins that would indicate a loss of machinery that is generally conserved across eukaryotic diversity, even after controlling for potentially incomplete genome representation. In particular, the complete DSL1 complex was missing in all surveyed ciliates. This protein complex has been shown as involved in peroxisome biogenesis in some model systems, and a paucity of DSL1 components has been indicative of degenerate peroxisome. However, Tetrahymena thermophila (formerly Tetrahymena pyroformis) was one of the original models for visualizing peroxisomes. Conversely, the AP3 complex essential for mucocyst maturation in T. thermophila, is poorly conserved despite the presence of secretory lysosome-related organelles across ciliate diversity. We discuss potential resolutions for these apparent paradoxes in the context of the heterogenous distribution of MTS machinery across the diversity of ciliates.</p>","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"23 4","pages":"208-220"},"PeriodicalIF":4.5,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39895916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TrafficPub Date : 2022-04-01Epub Date: 2022-02-21DOI: 10.1111/tra.12836
Maya Cabot, Volker Kiessling, Judith M White, Lukas K Tamm
{"title":"Endosomes supporting fusion mediated by vesicular stomatitis virus glycoprotein have distinctive motion and acidification.","authors":"Maya Cabot, Volker Kiessling, Judith M White, Lukas K Tamm","doi":"10.1111/tra.12836","DOIUrl":"10.1111/tra.12836","url":null,"abstract":"<p><p>Most enveloped viruses infect cells by binding receptors at the cell surface and undergo trafficking through the endocytic pathway to a compartment with the requisite conditions to trigger fusion with a host endosomal membrane. Broad categories of compartments in the endocytic pathway include early and late endosomes, which can be further categorized into subpopulations with differing rates of maturation and motility characteristics. Endocytic compartments have varying protein and lipid components, luminal ionic conditions and pH that provide uniquely hospitable environments for specific viruses to fuse. In order to characterize compartments that permit fusion, we studied the trafficking and fusion of viral particles pseudotyped with the vesicular stomatitis virus glycoprotein (VSV-G) on their surface and equipped with a novel pH sensor and a fluorescent content marker to measure pH, motion and fusion at the single particle level in live cells. We found that the VSV-G particles fuse predominantly from more acidic and more motile endosomes, and that a significant fraction of particles is trafficked to more static and less acidic endosomes that do not support their fusion. Moreover, the fusion-supporting endosomes undergo directed motion.</p>","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"23 4","pages":"221-234"},"PeriodicalIF":4.5,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10621750/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39909085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TrafficPub Date : 2022-03-08DOI: 10.1111/tra.12838
S. Barmaver, Muniesh Muthaiyan Shanmugam, Yen Chang, Odvogmed Bayansan, Prerana Bhan, Gong-Her Wu, O. I. Wagner
{"title":"Loss of intermediate filament IFB‐1 reduces mobility, density, and physiological function of mitochondria in Caenorhabditis elegans sensory neurons","authors":"S. Barmaver, Muniesh Muthaiyan Shanmugam, Yen Chang, Odvogmed Bayansan, Prerana Bhan, Gong-Her Wu, O. I. Wagner","doi":"10.1111/tra.12838","DOIUrl":"https://doi.org/10.1111/tra.12838","url":null,"abstract":"Mitochondria and intermediate filament (IF) accumulations often occur during imbalanced axonal transport leading to various types of neurological diseases. It is still poorly understood whether a link between neuronal IFs and mitochondrial mobility exist. In Caenorhabditis elegans, among the 11 cytoplasmic IF family proteins, IFB‐1 is of particular interest as it is expressed in a subset of sensory neurons. Depletion of IFB‐1 leads to mild dye‐filling and significant chemotaxis defects as well as reduced life span. Sensory neuron development is affected and mitochondrial transport is slowed down leading to reduced densities of these organelles. Mitochondria tend to cluster in neurons of IFB‐1 mutants likely independent of the fission and fusion machinery. Oxygen consumption and mitochondrial membrane potential is measurably reduced in worms carrying mutations in the ifb‐1 gene. Membrane potential also seems to play a role in transport such as carbonyl cyanide p‐(trifluoromethoxy)phenylhydrazone treatment led to increased directional switching of mitochondria. Mitochondria co‐localize with IFB‐1 in worm neurons and appear in a complex with IFB‐1 in pull‐down assays. In summary, we propose a model in which neuronal IFs may serve as critical (transient) anchor points for mitochondria during their long‐range transport in neurons for steady and balanced transport.","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"56 1","pages":"270 - 286"},"PeriodicalIF":4.5,"publicationDate":"2022-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72945105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TrafficPub Date : 2022-03-01Epub Date: 2022-02-02DOI: 10.1111/tra.12832
María de Los Ángeles Juricic Urzúa, Javiera Gallardo Rojas, Andrés Couve Correa, Mauricio Cerda, Steffen Härtel Gründler, Carolina González-Silva
{"title":"The dendritic ERGIC: Microtubule and actin cytoskeletons participate in stop-and-go movement of mobile carriers between stable structures.","authors":"María de Los Ángeles Juricic Urzúa, Javiera Gallardo Rojas, Andrés Couve Correa, Mauricio Cerda, Steffen Härtel Gründler, Carolina González-Silva","doi":"10.1111/tra.12832","DOIUrl":"https://doi.org/10.1111/tra.12832","url":null,"abstract":"<p><p>The endoplasmic reticulum (ER)-to-Golgi intermediate compartment (ERGIC) is a membranous organelle that mediates protein transport between the ER and the Golgi apparatus. In neurons, clusters of these vesiculotubular structures are situated throughout the cell in proximity to the ER, passing cargo to the cis-Golgi cisternae, located mainly in the perinuclear region. Although ERGIC markers have been identified in neurons, the distribution and dynamics of neuronal ERGIC structures have not been characterized yet. Here, we show that long-distance ERGIC transport occurs via an intermittent mechanism in dendrites, with mobile elements moving between stationary structures. Slow and fast live-cell imaging have captured stable ERGIC structures remaining in place over long periods of time, as well as mobile ERGIC structures advancing very short distances along dendrites. These short distances have been consistent with the lengths between the stationary ERGIC structures. Kymography revealed ERGIC elements that moved intermittently, emerging from and fusing with stationary ERGIC structures. Interestingly, this movement apparently depends not only on the integrity of the microtubule cytoskeleton, as previously reported, but on the actin cytoskeleton as well. Our results indicate that the dendritic ERGIC has a dual nature, with both stationary and mobile structures. The neural ERGIC network transports proteins via a stop-and-go movement in which both the microtubule and the actin cytoskeletons participate.</p>","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"23 3","pages":"174-187"},"PeriodicalIF":4.5,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39858014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ERGIC2 and ERGIC3 regulate the ER-to-Golgi transport of gap junction proteins in metazoans.","authors":"Liying Guan, Yongzhi Yang, Jingjing Liang, Yue Miao, Angyang Shang, Baolei Wang, Yingchun Wang, Mei Ding","doi":"10.1111/tra.12830","DOIUrl":"https://doi.org/10.1111/tra.12830","url":null,"abstract":"<p><p>The extremely dynamic life cycle of gap junction connections requires highly efficient intracellular trafficking system especially designed for gap junction proteins, but the underlying mechanisms are largely unknown. Here, we identified that the COPII-associated proteins ERGIC2 (ER-Golgi intermediate compartment) and ERGIC3 are specifically required for the efficient intracellular transport of gap junction proteins in both Caenorhabditis elegans and mice. In the absence of Ergic2 or Ergic3, gap junction proteins accumulate in the ER and Golgi apparatus and the size of endogenous gap junction plaques is reduced. Knocking out the Ergic2 or Ergic3 in mice results in heart enlargement and cardiac malfunction accompanied by reduced number and size of connexin 43 (Cx43) gap junctions. Invertebrates' gap junction protein innexins share no sequence similarity with vertebrates' connexins. However, ERGIC2 and ERGIC3 could bind to gap junction proteins in both worms and mice. Characterization of the highly specialized roles of ERGIC2 and ERGIC3 in metazoans reveals how the early secretory pathway could be adapted to facilitate the efficient transport for gap junction proteins in vivo.</p>","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"23 3","pages":"140-157"},"PeriodicalIF":4.5,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39794827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TrafficPub Date : 2022-03-01Epub Date: 2022-02-13DOI: 10.1111/tra.12831
Lou Fourriere, Ellie Hyun-Jung Cho, Paul A Gleeson
{"title":"Segregation of the membrane cargoes, BACE1 and amyloid precursor protein (APP) throughout the Golgi apparatus.","authors":"Lou Fourriere, Ellie Hyun-Jung Cho, Paul A Gleeson","doi":"10.1111/tra.12831","DOIUrl":"https://doi.org/10.1111/tra.12831","url":null,"abstract":"<p><p>The intracellular trafficking of β-site amyloid precursor protein (APP) cleaving enzyme (BACE1) and APP regulates amyloid-β production. Our previous work demonstrated that newly synthesized BACE1 and APP are segregated into distinct trafficking pathways from the trans-Golgi network (TGN), and that alterations in their trafficking lead to an increase in Aβ production in non-neuronal and neuronal cells. However, it is not known whether BACE1 and APP are transported through the Golgi stacks together and sorted at the TGN or segregated prior to arrival at the TGN. To address this question, we have used high-resolution Airyscan technology followed by Huygens deconvolution to quantify the overlap of BACE1 and APP in Golgi subcompartments in HeLa cells and primary neurons. Here, we show that APP and BACE1 are segregated, on exit from the endoplasmic reticulum and in the cis-Golgi and throughout the Golgi stack. In contrast, the transferrin receptor, which exits the TGN in AP-1 mediated transport carriers as for BACE1, colocalizes with BACE1, but not APP, throughout the Golgi stack. The segregation of APP and BACE1 is independent of the Golgi ribbon structure and the cytoplasmic domain of the cargo. Overall, our findings reveal the segregation of different membrane cargoes early in the secretory pathway, a finding relevant to the regulation of APP processing events.</p>","PeriodicalId":23207,"journal":{"name":"Traffic","volume":"23 3","pages":"158-173"},"PeriodicalIF":4.5,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9303681/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39734652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}