scholarly journals A paralog-specific role of COPI vesicles in the neuronal differentiation of mouse pluripotent cells

2020 ◽  
Vol 3 (9) ◽  
pp. e202000714
Author(s):  
Manu Jain Goyal ◽  
Xiyan Zhao ◽  
Mariya Bozhinova ◽  
Karla Andrade-López ◽  
Cecilia de Heus ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Genome Editing ◽  
Neuronal Differentiation ◽  
Membrane Trafficking ◽  
Protein Complex ◽  
Complex I ◽  
Pluripotent Cells ◽  
Neuronal Polarization

Coat protein complex I (COPI)–coated vesicles mediate membrane trafficking between Golgi cisternae as well as retrieval of proteins from the Golgi to the endoplasmic reticulum. There are several flavors of the COPI coat defined by paralogous subunits of the protein complex coatomer. However, whether paralogous COPI proteins have specific functions is currently unknown. Here, we show that the paralogous coatomer subunits γ1-COP and γ2-COP are differentially expressed during the neuronal differentiation of mouse pluripotent cells. Moreover, through a combination of genome editing experiments, we demonstrate that whereas γ-COP paralogs are largely functionally redundant, γ1-COP specifically promotes neurite outgrowth. Our work stresses a role of the COPI pathway in neuronal polarization and provides evidence for distinct functions for coatomer paralogous subunits in this process.

scholarly journals A paralog-specific role of the COPI pathway in the neuronal differentiation of murine pluripotent cells

2020 ◽  
Author(s):  
Manu Goyal ◽  
Xiyan Zhao ◽  
Mariya Bozhinova ◽  
Karla Lisette Andrade López ◽  
Cecilia de Heus ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Genome Editing ◽  
Neuronal Differentiation ◽  
Membrane Trafficking ◽  
Protein Complex ◽  
Complex I ◽  
Pluripotent Cells ◽  
Neuronal Polarization

ABSTRACTCoat protein complex I (COPI)-coated vesicles mediate membrane trafficking between Golgi cisternae as well as retrieval of proteins from the Golgi to the endoplasmic reticulum. There are several flavors of the COPI coat defined by paralogous subunits of the protein complex coatomer. However, whether paralogous COPI proteins have specific functions is currently unknown. Here we show that the paralogous coatomer subunits γ1-COP and γ2-COP are differentially expressed during the neuronal differentiation of mouse pluripotent cells. Moreover, through a combination of genome editing experiments, we demonstrate that whereas γ-COP paralogs are largely functionally redundant, γ1-COP specifically promotes neurite outgrowth. Our work stresses a role of the COPI pathway in neuronal polarization and provides evidence for distinct functions for coatomer paralogous subunits in this process.

scholarly journals Not just a cargo receptor for large cargoes; an emerging role of TANGO1 as an organizer of ER exit sites

2019 ◽  
Vol 166 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Kota Saito ◽  
Miharu Maeda
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Protein Complex ◽  
Vesicle Formation ◽  
Wide Range ◽  
Copii Vesicle ◽  
Cargo Receptor ◽  
Er Exit Sites ◽  
Golgi Organization

Abstract Proteins synthesized within the endoplasmic reticulum (ER) are exported from ER exit sites via coat protein complex II (COPII)-coated vesicles. Although the mechanisms of COPII-vesicle formation at the ER exit sites are highly conserved among species, vertebrate cells secrete a wide range of materials, including collagens and chylomicrons, which form bulky structures within the ER that are too large to fit into conventional carriers. Transport ANd Golgi Organization 1 (TANGO1) was initially identified as a cargo receptor for collagens but has been recently rediscovered as an organizer of ER exit sites. We would like to review recent advances in the mechanism of large cargo secretion and organization of ER exit sites through the function of TANGO1.

Role of EBAG9 protein in coat protein complex I‐dependent glycoprotein maturation and secretion processes in tumor cells

2010 ◽  
Vol 24 (10) ◽  
pp. 4000-4019 ◽  
Author(s):  
Jana Wolf ◽  
Tatiana A. Remier ◽  
Sebastian Schuck ◽  
Constantin Rüder ◽  
Kerstin Gerlach ◽  
...  
Keyword(s):  
Coat Protein ◽  
Tumor Cells ◽  
Protein Complex ◽  
Complex I ◽  
Coat Protein Complex

scholarly journals Sec16 influences transitional ER sites by regulating rather than organizing COPII

2013 ◽  
Vol 24 (21) ◽  
pp. 3406-3419 ◽  
Author(s):  
Nike Bharucha ◽  
Yang Liu ◽  
Effrosyni Papanikou ◽  
Conor McMahon ◽  
Masatoshi Esaki ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Pichia Pastoris ◽  
Protein Complex ◽  
The Other ◽  
Yeast Pichia Pastoris ◽  
Functional Regions ◽  
Conserved Domain ◽  
Copii Vesicles ◽  
Negative Regulatory Role

During the budding of coat protein complex II (COPII) vesicles from transitional endoplasmic reticulum (tER) sites, Sec16 has been proposed to play two distinct roles: negatively regulating COPII turnover and organizing COPII assembly at tER sites. We tested these ideas using the yeast Pichia pastoris. Redistribution of Sec16 to the cytosol accelerates tER dynamics, supporting a negative regulatory role for Sec16. To evaluate a possible COPII organization role, we dissected the functional regions of Sec16. The central conserved domain, which had been implicated in coordinating COPII assembly, is actually dispensable for normal tER structure. An upstream conserved region (UCR) localizes Sec16 to tER sites. The UCR binds COPII components, and removal of COPII from tER sites also removes Sec16, indicating that COPII recruits Sec16 rather than the other way around. We propose that Sec16 does not in fact organize COPII. Instead, regulation of COPII turnover can account for the influence of Sec16 on tER sites.

scholarly journals Nm23H2 Facilitates Coat Protein Complex II Assembly and Endoplasmic Reticulum Export in Mammalian Cells

2005 ◽  
Vol 16 (2) ◽  
pp. 835-848 ◽  
Author(s):  
Lori Kapetanovich ◽  
Cassandra Baughman ◽  
Tina H. Lee
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Protein Complex ◽  
Mammalian Cells ◽  
Complex Ii ◽  
Permeabilized Cells ◽  
Er Export ◽  
Coat Protein Complex

The cytosolic coat protein complex II (COPII) mediates vesicle formation from the endoplasmic reticulum (ER) and is essential for ER-to-Golgi trafficking. The minimal machinery for COPII assembly is well established. However, additional factors may regulate the process in mammalian cells. Here, a morphological COPII assembly assay using purified COPII proteins and digitonin-permeabilized cells has been applied to demonstrate a role for a novel component of the COPII assembly pathway. The factor was purified and identified by mass spectrometry as Nm23H2, one of eight isoforms of nucleoside diphosphate kinase in mammalian cells. Importantly, recombinant Nm23H2, as well as a catalytically inactive version, promoted COPII assembly in vitro, suggesting a noncatalytic role for Nm23H2. Consistent with a function for Nm23H2 in ER export, Nm23H2 localized to a reticular network that also stained for the ER marker calnexin. Finally, an in vivo role for Nm23H2 in COPII assembly was confirmed by isoform-specific knockdown of Nm23H2 by using short interfering RNA. Knockdown of Nm23H2, but not its most closely related isoform Nm23H1, resulted in diminished COPII assembly at steady state and reduced kinetics of ER export. These results strongly suggest a previously unappreciated role for Nm23H2 in mammalian ER export.

scholarly journals Differential roles of ArfGAP1, ArfGAP2, and ArfGAP3 in COPI trafficking

2008 ◽  
Vol 183 (4) ◽  
pp. 725-735 ◽  
Author(s):  
Carolin Weimer ◽  
Rainer Beck ◽  
Priska Eckert ◽  
Ingeborg Reckmann ◽  
Jörg Moelleken ◽  
...  
Keyword(s):  
Coat Protein ◽  
Protein Complex ◽  
Complex I ◽  
Adenosine Diphosphate ◽  
General Function ◽  
Golgi Membrane ◽  
Gtpase Activating Protein ◽  
Gtp Hydrolysis ◽  
Copi Vesicle ◽  
Guanosine Triphosphatase

The formation of coat protein complex I (COPI)–coated vesicles is regulated by the small guanosine triphosphatase (GTPase) adenosine diphosphate ribosylation factor 1 (Arf1), which in its GTP-bound form recruits coatomer to the Golgi membrane. Arf GTPase-activating protein (GAP) catalyzed GTP hydrolysis in Arf1 triggers uncoating and is required for uptake of cargo molecules into vesicles. Three mammalian ArfGAPs are involved in COPI vesicle trafficking; however, their individual functions remain obscure. ArfGAP1 binds to membranes depending on their curvature. In this study, we show that ArfGAP2 and ArfGAP3 do not bind directly to membranes but are recruited via interactions with coatomer. In the presence of coatomer, ArfGAP2 and ArfGAP3 activities are comparable with or even higher than ArfGAP1 activity. Although previously speculated, our results now demonstrate a function for coatomer in ArfGAP-catalyzed GTP hydrolysis by Arf1. We suggest that ArfGAP2 and ArfGAP3 are coat protein–dependent ArfGAPs, whereas ArfGAP1 has a more general function.

Coat protein complex I facilitates dengue virus production

2018 ◽  
Vol 250 ◽  
pp. 13-20 ◽  
Author(s):  
Nopprarat Tongmuang ◽  
Umpa Yasamut ◽  
Pucharee Songprakhon ◽  
Thanyaporn Dechtawewat ◽  
Shilu Malakar ◽  
...  
Keyword(s):  
Coat Protein ◽  
Dengue Virus ◽  
Protein Complex ◽  
Complex I ◽  
Virus Production ◽  
Coat Protein Complex
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