scholarly journals Rha1, an Arabidopsis Rab5 Homolog, Plays a Critical Role in the Vacuolar Trafficking of Soluble Cargo Proteins

2003 ◽  
Vol 15 (5) ◽  
pp. 1057-1070 ◽  
Author(s):  
Eun Ju Sohn ◽  
Eol Sun Kim ◽  
Min Zhao ◽  
Soo Jin Kim ◽  
Hyeran Kim ◽  
...  
Keyword(s):  
Critical Role ◽  
Cargo Proteins ◽  
Vacuolar Trafficking

scholarly journals TGN/EE SNARE protein SYP61 is ubiquitinated and required for carbon/nitrogen-nutrient responses in Arabidopsis

2020 ◽  
Author(s):  
Yoko Hasegawa ◽  
Thais Huarancca Reyes ◽  
Tomohiro Uemura ◽  
Akari Fujimaki ◽  
Yongming Luo ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Critical Role ◽  
Snare Protein ◽  
Post Translational Modification ◽  
Cellular Processes ◽  
Protein Receptor ◽  
Sensitive Factor ◽  
Cargo Proteins ◽  
Golgi Network

AbstractUbiquitination is a post-translational modification with reversible attachment of the small protein ubiquitin, which is involved in numerous cellular processes including membrane trafficking. For example, ubiquitination of cargo proteins is known to regulate their subcellular dynamics, and plays important roles in plant growth and stress adaptation. However, the regulatory mechanism of the trafficking machinery components remains elusive. Here, we report Arabidopsis trans-Golgi network/early endosome (TGN/EE) localized soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) protein SYP61 as a novel ubiquitination target of a membrane localized ubiquitin ligase ATL31. SYP61 is a key component of membrane trafficking in Arabidopsis. SYP61 was ubiquitinated with K63-linked chain by ATL31 in vitro and in plants. The knockdown mutants of SYP61 were hypersensitive to the disrupted carbon (C)/nitrogen (N)-nutrient stress, suggesting its critical role in plant homeostasis in response to nutrients. We also found the ubiquitination status of SYP61 is affected by C/N-nutrient availability. These results provided possibility that ubiquitination of SNARE protein has important role in plant physiology.

Abstract P751: Global Analyses of Protein and Microrna Cargo in Neural Stem Cell Derived-Exosomes After Brain Ischemia

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Xianshuang S LIU ◽  
Baoyan Fan ◽  
Chao Li ◽  
Albert Levin ◽  
Rui Lan Zhang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Pathway Analysis ◽  
Critical Role ◽  
Neuronal Cell ◽  
Artery Occlusion ◽  
Mirna Array ◽  
Transmission Electron ◽  
Cargo Proteins ◽  
Pathway Analyses ◽  
Neurovascular Remodeling

Background: Adult neurogenesis facilitates brain remodeling after stroke. Exosomes derived from neural stem cells (NSCs) promote ischemic neurovascular remodeling including angiogenesis and axonal outgrowth, potentially by transferring their cargo proteins and miRNAs to recipient cells. However, cargo profiles of proteins and miRNAs in NSC exosomes have not been investigated. Methods: Exosomes were isolated from supernatants of cultured NSCs harvested from the subventricular zone of rats subjected to 7 day middle cerebral artery occlusion (MCAO) and non-MCAO rats, respectively. Mass spectrometry and miRNA array were utilized to determine the protein and miRNA profiles of NSC-derived exosomes (NSC-Exos). Bioinformatic pathway analyses were performed using Ingenuity Pathway Analysis (IPA). Results: Exosome markers and size distribution (50-200nm) were validated with Western blot, transmission electron microscopy and Nanosight measurements, respectively. Proteomics analysis yielded a total of 1,770 proteins in ischemic NSC-Exos. Bioinformatics analysis identified 24, 23 and 23 proteins that were related to neuronal cell proliferation, migration and differentiation, respectively. Intriguingly, enrichment signaling pathway analysis revealed cargo proteins in ischemic NSC-Exos were highly associated with dysfunction, membrane, and permeability of mitochondrion, indicating a critical role of extracellular mitochondrion in stroke-induced neurogenesis. In addition, 318 miRNAs were detected in ischemic NSC-Exos. Gene ontology analysis demonstrated that differentially expressed miRNAs between ischemic and non-ischemic NSC-Exos were highly related to inflammation, cell proliferation, cell cycle, and differentiation. The top 3 upregulated miRNAs including miR-106b, miR-542,miR-125b were validated in ischemic NSC-Exos using RT-PCR. The functions of these miRNAs are related to the induction of angiogenesis. Summary/Conclusion: Our results for the first time demonstrate that ischemic NSC-Exos contain a robust profile of protein and miRNA effectors, which may provide new insights into the function of NSC-Exos in stroke-induced neurogenesis and potentially lead to new therapeutic targets against stroke.

scholarly journals Arabidopsis EPSIN1 Plays an Important Role in Vacuolar Trafficking of Soluble Cargo Proteins in Plant Cells via Interactions with Clathrin, AP-1, VTI11, and VSR1

2006 ◽  
Vol 18 (9) ◽  
pp. 2258-2274 ◽  
Author(s):  
Jinhee Song ◽  
Myoung Hui Lee ◽  
Gil-Je Lee ◽  
Cheol Min Yoo ◽  
Inhwan Hwang
Keyword(s):  
Plant Cells ◽  
Cargo Proteins ◽  
Vacuolar Trafficking

scholarly journals Actin Filaments Play a Critical Role in Vacuolar Trafficking at the Golgi Complex in Plant Cells

2005 ◽  
Vol 17 (3) ◽  
pp. 888-902 ◽  
Author(s):  
Hyeran Kim ◽  
Misoon Park ◽  
Soo Jin Kim ◽  
Inhwan Hwang
Keyword(s):  
Golgi Complex ◽  
Actin Filaments ◽  
Critical Role ◽  
Plant Cells ◽  
Vacuolar Trafficking

scholarly journals Endosomal PI(3)P regulation by the COMMD/CCDC22/CCDC93 (CCC) complex controls membrane protein recycling

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Amika Singla ◽  
Alina Fedoseienko ◽  
Sai S. P. Giridharan ◽  
Brittany L. Overlee ◽  
Adam Lopez ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Mechanism Of Action ◽  
Critical Role ◽  
Molecular Assemblies ◽  
Actin Nucleation ◽  
Effector Molecules ◽  
Endosomal Compartment ◽  
Cargo Proteins ◽  
Nucleation Promoting Factor ◽  
Phosphatidylinositol 3

Abstract Protein recycling through the endolysosomal system relies on molecular assemblies that interact with cargo proteins, membranes, and effector molecules. Among them, the COMMD/CCDC22/CCDC93 (CCC) complex plays a critical role in recycling events. While CCC is closely associated with retriever, a cargo recognition complex, its mechanism of action remains unexplained. Herein we show that CCC and retriever are closely linked through sharing a common subunit (VPS35L), yet the integrity of CCC, but not retriever, is required to maintain normal endosomal levels of phosphatidylinositol-3-phosphate (PI(3)P). CCC complex depletion leads to elevated PI(3)P levels, enhanced recruitment and activation of WASH (an actin nucleation promoting factor), excess endosomal F-actin and trapping of internalized receptors. Mechanistically, we find that CCC regulates the phosphorylation and endosomal recruitment of the PI(3)P phosphatase MTMR2. Taken together, we show that the regulation of PI(3)P levels by the CCC complex is critical to protein recycling in the endosomal compartment.

scholarly journals Pan1 regulates transitions between stages of clathrin-mediated endocytosis

2015 ◽  
Vol 26 (7) ◽  
pp. 1371-1385 ◽  
Author(s):  
Mary Katherine Bradford ◽  
Karen Whitworth ◽  
Beverly Wendland
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Plant Hormone ◽  
Specific Binding ◽  
Critical Role ◽  
Model System ◽  
Scaffolding Protein ◽  
Binding Interactions ◽  
Cargo Proteins ◽  
Distinct Role

Endocytosis is a well-conserved process by which cells invaginate small portions of the plasma membrane to create vesicles containing extracellular and transmembrane cargo proteins. Dozens of proteins and hundreds of specific binding interactions are needed to coordinate and regulate these events. Saccharomyces cerevisiae is a powerful model system with which to study clathrin-mediated endocytosis (CME). Pan1 is believed to be a scaffolding protein due to its interactions with numerous proteins that act throughout the endocytic process. Previous research characterized many Pan1 binding interactions, but due to Pan1's essential nature, the exact mechanisms of Pan1's function in endocytosis have been difficult to define. We created a novel Pan1-degron allele, Pan1-AID, in which Pan1 can be specifically and efficiently degraded in <1 h upon addition of the plant hormone auxin. The loss of Pan1 caused a delay in endocytic progression and weakened connections between the coat/actin machinery and the membrane, leading to arrest in CME. In addition, we determined a critical role for the central region of Pan1 in endocytosis and viability. The regions important for endocytosis and viability can be separated, suggesting that Pan1 may have a distinct role in the cell that is essential for viability.

scholarly journals Atlastin-mediated membrane tethering is critical for cargo mobility and exit from the endoplasmic reticulum

2019 ◽  
Vol 116 (28) ◽  
pp. 14029-14038 ◽  
Author(s):  
Liling Niu ◽  
Tianji Ma ◽  
Feng Yang ◽  
Bing Yan ◽  
Xiao Tang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Hereditary Spastic Paraplegia ◽  
Critical Role ◽  
Spastic Paraplegia ◽  
Exit Site ◽  
Cargo Proteins ◽  
Membrane Tethering ◽  
Copii Vesicles ◽  
Er Export ◽  
In Cells

Endoplasmic reticulum (ER) membrane junctions are formed by the dynamin-like GTPase atlastin (ATL). Deletion of ATL results in long unbranched ER tubules in cells, and mutation of human ATL1 is linked to hereditary spastic paraplegia. Here, we demonstrate that COPII formation is drastically decreased in the periphery of ATL-deleted cells. ER export of cargo proteins becomes defective; ER exit site initiation is not affected, but many of the sites fail to recruit COPII subunits. The efficiency of cargo packaging into COPII vesicles is significantly reduced in cells lacking ATLs, or when the ER is transiently fragmented. Cargo is less mobile in the ER in the absence of ATL, but the cargo mobility and COPII formation can be restored by ATL R77A, which is capable of tethering, but not fusing, ER tubules. These findings suggest that the generation of ER junctions by ATL plays a critical role in maintaining the necessary mobility of ER contents to allow efficient packaging of cargo proteins into COPII vesicles.

scholarly journals ARF Is Required for Maintenance of Yeast Golgi and Endosome Structure and Function

1998 ◽  
Vol 9 (3) ◽  
pp. 653-670 ◽  
Author(s):  
Erin C. Gaynor ◽  
Chih-Ying Chen ◽  
Scott D. Emr ◽  
Todd R. Graham
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Transport ◽  
Critical Role ◽  
Hollow Spheres ◽  
Retrograde Transport ◽  
Membrane Dynamics ◽  
Growth Defect ◽  
Anterograde Transport ◽  
Cargo Proteins ◽  
Mutant Cells

ADP ribosylation factor (ARF) is thought to play a critical role in recruiting coatomer (COPI) to Golgi membranes to drive transport vesicle budding. Yeast strains harboring mutant COPI proteins exhibit defects in retrograde Golgi to endoplasmic reticulum protein transport and striking cargo-selective defects in anterograde endoplasmic reticulum to Golgi protein transport. To determine whetherarf mutants exhibit similar phenotypes, the anterograde transport kinetics of multiple cargo proteins were examined inarf mutant cells, and, surprisingly, both COPI-dependent and COPI-independent cargo proteins exhibited comparable defects. Retrograde dilysine-mediated transport also appeared to be inefficient in the arf mutants, and coatomer mutants with no detectable anterograde transport defect exhibited a synthetic growth defect when combined with arf1Δ, supporting a role for ARF in retrograde transport. Remarkably, we found that early and medial Golgi glycosyltransferases localized to abnormally large ring-shaped structures. The endocytic marker FM4–64 also stained similar, but generally larger ring-shaped structures en route from the plasma membrane to the vacuole in arf mutants. Brefeldin A similarly perturbed endosome morphology and also inhibited transport of FM4–64 from endosomal structures to the vacuole. Electron microscopy of arf mutant cells revealed the presence of what appear to be hollow spheres of interconnected membrane tubules which likely correspond to the fluorescent ring structures. Together, these observations indicate that organelle morphology is significantly more affected than transport in the arf mutants, suggesting a fundamental role for ARF in regulating membrane dynamics. Possible mechanisms for producing this dramatic morphological change in intracellular organelles and its relation to the function of ARF in coat assembly are discussed.

scholarly journals ARFGAP1 plays a central role in coupling COPI cargo sorting with vesicle formation

2005 ◽  
Vol 168 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Stella Y. Lee ◽  
Jia-Shu Yang ◽  
Wanjin Hong ◽  
Richard T. Premont ◽  
Victor W. Hsu
Keyword(s):  
Critical Role ◽  
Vesicle Formation ◽  
Golgi Membrane ◽  
Gtpase Activating Protein ◽  
Direct Role ◽  
Effector Functions ◽  
Cargo Proteins ◽  
Adp Ribosylation Factor ◽  
Prevailing View ◽  
Cargo Sorting

Examining how key components of coat protein I (COPI) transport participate in cargo sorting, we find that, instead of ADP ribosylation factor 1 (ARF1), its GTPase-activating protein (GAP) plays a direct role in promoting the binding of cargo proteins by coatomer (the core COPI complex). Activated ARF1 binds selectively to SNARE cargo proteins, with this binding likely to represent at least a mechanism by which activated ARF1 is stabilized on Golgi membrane to propagate its effector functions. We also find that the GAP catalytic activity plays a critical role in the formation of COPI vesicles from Golgi membrane, in contrast to the prevailing view that this activity antagonizes vesicle formation. Together, these findings indicate that GAP plays a central role in coupling cargo sorting and vesicle formation, with implications for simplifying models to describe how these two processes are coupled during COPI transport.

Sign in / Sign up

Export Citation Format

Share Document