Article
Cell Biology
Tomohiro Yorimitsu, Ken Sato
Summary: COPII proteins assemble at ER exit sites to form transport carriers. Sec12 triggers the initiation of COPII assembly in yeast and Sec16 plays a critical role in COPII organization. We found that a Sec12 homolog, Sed4, concentrates at ERES and mediates the ERES localization of Sec16. Our findings provide insight into the interdependent function of Sec16 and Sed4 at ERES.
JOURNAL OF CELL SCIENCE
(2023)
Article
Biophysics
Konstantin Speckner, Lorenz Stadler, Matthias Weiss
Summary: This study reveals the complex structure of the ER in mammalian cells and its impact on the distribution of ERESs, suggesting that the spatial pattern of ERESs is determined by ER morphology and maintained by hindering the process of domain coarsening. This mechanism ensures a proper functioning of ERES patterns in the early secretory pathway under various conditions.
BIOPHYSICAL JOURNAL
(2021)
Article
Cell Biology
Raffaella Gallo, Arpan Kumar Rai, Alexa B. R. Mcintyre, Katrina Meyer, Lucas Pelkmans
Summary: The dual-specificity kinase DYRK3 plays an important role in regulating the formation and dissolution of biomolecular condensates, affecting processes such as stress recovery and mitotic progression. This study shows that DYRK3 interacts with proteins associated with endoplasmic reticulum exit sites (ERESs), and its inhibition disrupts the organization of the ERES-Golgi interface and secretory trafficking. The regulation of ERES by DYRK3 depends on the N-terminal intrinsically disordered region (IDR) of the peripheral membrane protein SEC16A, which forms liquid-like condensates with ERES components. The findings suggest that the physical state of ERES is crucial for efficient membrane traffic in eukaryotic cells, and DYRK3 phosphorylation plays a role in modulating these material properties.
DEVELOPMENTAL CELL
(2023)
Article
Biochemistry & Molecular Biology
Dalal Bakhos-Douaihy, Elie Seaayfan, Nadia Frachon, Sylvie Demaretz, Martin Koemhoff, Kamel Laghmani
Summary: This study reveals that NKCC2 relies on a COPII-dependent pathway for ER export, in addition to its dileucine-like motifs, it also requires di-acidic motifs. The findings suggest that mutations interfering with this pathway could be the molecular basis of BS1.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Plant Sciences
Alastair J. J. McGinness, Jennifer Schoberer, Charlotte Pain, Federica Brandizzi, Verena Kriechbaumer
Summary: In plant cells, the endoplasmic reticulum (ER) and Golgi bodies are closely connected and recent research has shown dynamic connections between pre-cis-Golgi cisternae and ERES. Fine tubular structures observed between the ER and Golgi as well as between the ER and ERES may be involved in stabilizing the physical connection between ER and ERES/Golgi cisternae, and may also play a role in cargo transport from the ER to Golgi bodies.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Biology
Giuseppina Amodio, Valentina Pagliara, Paolo Remondelli, Ornella Moltedo
Summary: The endoplasmic reticulum (ER) is essential for maintaining proteostasis in the secretory pathway through controlling protein folding. The unfolded protein response (UPR) pathways regulate the quality control of protein folding, and the multimeric complex COPII controls the exit of correctly folded proteins from the ER.
Article
Multidisciplinary Sciences
Natalia Gomez-Navarro, Julija Maldutyte, Kristina Poljak, Sew-Yeu Peak-Chew, Jonathon Orme, Brittany J. Bisnett, Caitlin H. Lamb, Michael Boyce, Davide Gianni, Elizabeth A. Miller
Summary: This study explores the possibility of selectively inhibiting protein secretion by perturbing protein-protein interactions involved in capture into transport vesicles. The researchers discovered a specific small molecule that can disrupt the function of the SEC24 protein, leading to decreased secretion of specific proteins.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Cell Biology
Eric M. Clark, Brian A. Link
Summary: The study investigated the genetic interactions of ctage5 and tango1 in zebrafish, revealing their diverse roles in organogenesis, collagen versus lipoprotein trafficking, stress-pathway activation, and survival. Although Ctage5 and Tango1 have overlapping functions in tissue development and homeostasis, they also exhibit divergent roles in these processes.
MOLECULAR BIOLOGY OF THE CELL
(2021)
Article
Cell Biology
Olga Shomron, Koret Hirschberg, Anton Burakov, Rimma Kamentseva, Elena Kornilova, Elena Nadezhdina, Ilya Brodsky
Summary: The endoplasmic reticulum (ER) is involved in the biogenesis, modification, and transport of secreted and membrane proteins. Transport carriers (TCs) form at ER exit sites (ERES) via a COPII-dependent mechanism and move to the Golgi apparatus on microtubule tracks. Dynein activity mediates the central concentration of ERES near the Golgi, enhancing the efficiency of ER-to-Golgi transport.
Review
Biochemistry & Molecular Biology
Sander E. Van Der Verren, Giulia Zanetti
Summary: Sar1, a small GTPase protein of the ARF family, plays a role in cargo concentration and membrane deformation by associating with the endoplasmic reticulum membrane and recruiting COPII components. The regulation of Sar1's GTP hydrolysis and its role in coat assembly, as well as the mechanism of Sar1-induced membrane deformation and scission, are still not fully understood, especially in higher organisms with a wider range of secreted cargoes. This review focuses on these aspects and highlights the additional specialization in higher eukaryotes, along with the outstanding questions regarding the orchestration of Sar1 functions.
Review
Biochemistry & Molecular Biology
I. Raote, V. Malhotra
Summary: The functions of COPII coat protein complex in eukaryotic protein secretion are conserved, but standard COPII vesicles cannot accommodate the secretion of metazoan-specific cargoes. Metazoans have evolved modules centered on proteins like TANGO1 to create a novel mode of cargo export at the endoplasmic reticulum by interacting with COPII coats and early secretory pathway membranes.
ANNUAL REVIEW OF BIOCHEMISTRY, VOL 90, 2021
(2021)
Article
Biochemistry & Molecular Biology
Mingqin Chang, Shu-Zon Wu, Samantha E. Ryken, Jacquelyn E. O'Sullivan, Magdalena Bezanilla
Summary: Plant COPII complex in moss Physcomitrium patens displays isoform-specific contributions to polarized growth, with different Sec23/24 gene families playing distinct roles in development. The presence of divergent Sec23 clades in land plants suggests functional diversification within the COPII complex.
Article
Cell Biology
Ke Yang, Min Liu, Zhi Feng, Marta Rojas, Lingjian Zhou, Hongmei Ke, Jose Carlos Pastor-Pareja
Summary: Secretory cargos are collected at ERES before transport to Golgi. In Drosophila models, a pre-cis-Golgi region equivalent to the ERGIC in vertebrates is involved in both anterograde and retrograde transport, connecting ERES and the rest of the Golgi without evidence of separate compartments or large carriers. Many vesicles and pearled tubules are observed in this process.
Article
Multidisciplinary Sciences
Ojore Benedict Valentine Oka, Arvin Shedrach Pierre, Marie Anne Pringle, Wanida Tungkum, Zhenbo Cao, Bethany Fleming, Neil John Bulleid
Summary: The unfolded protein response (UPR) regulates cellular proteostasis by activating and trafficking the ATF6 alpha sensor. After ER stress, ATF6 alpha undergoes a redox switch to form a disulfide bonded dimer, which is then transported to the Golgi for cleavage. Overexpression of ERp18 affects dimer formation and limits Golgi trafficking.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Review
Cell Biology
Sharanya Chatterjee, Ana Jeemin Choi, Gad Frankel
Summary: The trafficking of cargo from the endoplasmic reticulum (ER) to the Golgi apparatus is a crucial cellular process involving the coat protein complex-II (COPII) and Sec24. Approximately one-third of mammalian proteins require the COPII-mediated secretory pathway for membrane insertion or secretion. There are distinct cargo interaction motifs for different Sec24 paralogs, leading to varying levels of specificity in cargo binding. Additionally, the Sec24 secretion system can be exploited by pathogens like viruses and bacteria.
Article
Biochemistry & Molecular Biology
Alaa Shaheen
Summary: Biocidal agents such as formaldehyde and glutaraldehyde can inactivate various coronaviruses, including SARS-CoV-2. The mechanism of inactivation involves inducing conformational changes in the spike glycoprotein through Schiff base reactions, preventing the virus from binding to cellular receptors. Additionally, a potential prophylactic and therapeutic measure using acetoacetate against SARS-CoV-2 is proposed, pending experimental confirmation, along with further research to find a broad-spectrum antivirus against multiple members of the orthocoronavirinae subfamily.
Review
Endocrinology & Metabolism
Alaa Shaheen, Ahmad M. A. Aljebali