scholarly journals Sec24C mediates a Golgi-independent trafficking pathway that is required for tonoplast localization of ABCC1 and ABCC2

2020 ◽  
Author(s):  
Qiao-Yan Lv ◽  
Yi-Qun Gao ◽  
Ya-Ling Wang ◽  
Chu-Ying Zhang ◽  
Zhen-Fei Chao ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Golgi Apparatus ◽  
Genetic Screening ◽  
Biological Process ◽  
Loss Of Function ◽  
Independent Manner ◽  
Trafficking Pathway ◽  
Copii Vesicles ◽  
Target Locations

Abstract Protein sorting is an essential biological process in all organisms. Trafficking membrane proteins generally relies on the sorting machinery of the Golgi apparatus. However, many proteins have been found to be delivered to target locations via Golgi-independent pathways, but the mechanisms underlying this delivery system remain unknown. Here, we report that Sec24C, a component of coat protein complex II (COPII) vesicles, mediates the direct secretory trafficking of the phytochelatin transporters ABCC1 and ABCC2 from the endoplasmic reticulum (ER) to prevacuolar compartments (PVCs). After performing a genetic screening, we found that Sec24C loss-of-function mutants are hypersensitive to cadmium (Cd) and arsenic (As) treatments due to mislocalization of ABCC1 and ABCC2, which results in defects in the vacuole compartmentalization of the toxic metals. Further studies showed that Sec24C recognizes ABCC1 and ABCC2 through direct interactions to mediate their exit from the ER to PVCs in a Golgi-independent manner. These findings expand our understanding of Golgi-independent trafficking as well as COPII vesicles.

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 Erv26p Directs Pro-Alkaline Phosphatase into Endoplasmic Reticulum–derived Coat Protein Complex II Transport Vesicles

2006 ◽  
Vol 17 (11) ◽  
pp. 4780-4789 ◽  
Author(s):  
Catherine A. Bue ◽  
Christine M. Bentivoglio ◽  
Charles Barlowe
Keyword(s):  
Alkaline Phosphatase ◽  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Membrane Protein ◽  
Protein Complex ◽  
Integral Membrane Protein ◽  
Secretory Proteins ◽  
Complex Ii ◽  
Transport Vesicles ◽  
Copii Vesicles

Secretory proteins are exported from the endoplasmic reticulum (ER) in transport vesicles formed by the coat protein complex II (COPII). We detected Erv26p as an integral membrane protein that was efficiently packaged into COPII vesicles and cycled between the ER and Golgi compartments. The erv26Δ mutant displayed a selective secretory defect in which the pro-form of vacuolar alkaline phosphatase (pro-ALP) accumulated in the ER, whereas other secretory proteins were transported at wild-type rates. In vitro budding experiments demonstrated that Erv26p was directly required for packaging of pro-ALP into COPII vesicles. Moreover, Erv26p was detected in a specific complex with pro-ALP when immunoprecipitated from detergent-solublized ER membranes. Based on these observations, we propose that Erv26p serves as a transmembrane adaptor to link specific secretory cargo to the COPII coat. Because ALP is a type II integral membrane protein in yeast, these findings imply that an additional class of secretory cargo relies on adaptor proteins for efficient export from the ER.

scholarly journals Phosphatidic acid phospholipase A1 mediates ER–Golgi transit of a family of G protein–coupled receptors

2014 ◽  
Vol 206 (1) ◽  
pp. 79-95 ◽  
Author(s):  
Govind Kunduri ◽  
Changqing Yuan ◽  
Velayoudame Parthibane ◽  
Katherine M. Nyswaner ◽  
Ritu Kanwar ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Membrane Proteins ◽  
Phosphatidic Acid ◽  
G Protein ◽  
Golgi Complex ◽  
G Protein Coupled Receptors ◽  
Phospholipase A1 ◽  
Copii Vesicles ◽  
G Protein Coupled

The coat protein II (COPII)–coated vesicular system transports newly synthesized secretory and membrane proteins from the endoplasmic reticulum (ER) to the Golgi complex. Recruitment of cargo into COPII vesicles requires an interaction of COPII proteins either with the cargo molecules directly or with cargo receptors for anterograde trafficking. We show that cytosolic phosphatidic acid phospholipase A1 (PAPLA1) interacts with COPII protein family members and is required for the transport of Rh1 (rhodopsin 1), an N-glycosylated G protein–coupled receptor (GPCR), from the ER to the Golgi complex. In papla1 mutants, in the absence of transport to the Golgi, Rh1 is aberrantly glycosylated and is mislocalized. These defects lead to decreased levels of the protein and decreased sensitivity of the photoreceptors to light. Several GPCRs, including other rhodopsins and Bride of sevenless, are similarly affected. Our findings show that a cytosolic protein is necessary for transit of selective transmembrane receptor cargo by the COPII coat for anterograde trafficking.

scholarly journals A Missense Mutation in the Arabidopsis COPII Coat Protein Sec24A Induces the Formation of Clusters of the Endoplasmic Reticulum and Golgi Apparatus

2009 ◽  
Vol 21 (11) ◽  
pp. 3655-3671 ◽  
Author(s):  
Carmen Faso ◽  
Ya-Ni Chen ◽  
Kentaro Tamura ◽  
Michael Held ◽  
Starla Zemelis ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Golgi Apparatus ◽  
Missense Mutation

scholarly journals Complementary and divergent functions of zebrafish Tango1 and Ctage5 in tissue development and homeostasis

2021 ◽  
pp. mbc.E20-11-0745
Author(s):  
Eric M. Clark ◽  
Brian A. Link
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Genetic Interaction ◽  
Interaction Study ◽  
Tissue Development ◽  
Pathway Activation ◽  
Copii Vesicles ◽  
Collagen Versus ◽  
Stress Pathway ◽  
And Cartilage

Coat protein complex II (COPII) factors mediate cargo export from the endoplasmic reticulum (ER), but bulky collagens and lipoproteins are too large for traditional COPII vesicles. Mammalian CTAGE5 and TANGO1 have been well characterized individually as specialized cargo receptors at the ER that function with COPII coats to facilitate trafficking of bulky cargoes. Here, we present a genetic interaction study in zebrafish of deletions in ctage5, tango1, or both to investigate their potential distinct and complementary functions. We found that Ctage5 and Tango1 have different roles related to organogenesis, collagen versus lipoprotein trafficking, stress-pathway activation, and survival. While disruption of both ctage5 and tango1 compounded phenotype severity, mutation of either factor alone revealed novel tissue specific defects in the building of heart, muscle, lens, and intestine, in addition to the previously described roles in the development of neural and cartilage tissues. Together, our results demonstrate that Ctage5 and Tango1 have overlapping functions, but also suggest divergent roles in tissue development and homeostasis.

scholarly journals Sorting of GPI-anchored proteins into ER exit sites by p24 proteins is dependent on remodeled GPI

2011 ◽  
Vol 194 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Morihisa Fujita ◽  
Reika Watanabe ◽  
Nina Jaensch ◽  
Maria Romanova-Michaelides ◽  
Tadashi Satoh ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Posttranslational Modification ◽  
Protein Complex ◽  
Er Exit Sites ◽  
Ph Dependent ◽  
Copii Vesicles ◽  
Attachment Proteins ◽  
Acidic Compartments ◽  
P24 Proteins

Glycosylphosphatidylinositol (GPI) anchoring of proteins is a posttranslational modification occurring in the endoplasmic reticulum (ER). After GPI attachment, proteins are transported by coat protein complex II (COPII)-coated vesicles from the ER. Because GPI-anchored proteins (GPI-APs) are localized in the lumen, they cannot interact with cytosolic COPII components directly. Receptors that link GPI-APs to COPII are thought to be involved in efficient packaging of GPI-APs into vesicles; however, mechanisms of GPI-AP sorting are not well understood. Here we describe two remodeling reactions for GPI anchors, mediated by PGAP1 and PGAP5, which were required for sorting of GPI-APs to ER exit sites. The p24 family of proteins recognized the remodeled GPI-APs and sorted them into COPII vesicles. Association of p24 proteins with GPI-APs was pH dependent, which suggests that they bind in the ER and dissociate in post-ER acidic compartments. Our results indicate that p24 complexes act as cargo receptors for correctly remodeled GPI-APs to be sorted into COPII vesicles.

scholarly journals TANGO1 and SEC12 are copackaged with procollagen I to facilitate the generation of large COPII carriers

2018 ◽  
Vol 115 (52) ◽  
pp. E12255-E12264 ◽  
Author(s):  
Lin Yuan ◽  
Samuel J. Kenny ◽  
Juliet Hemmati ◽  
Ke Xu ◽  
Randy Schekman
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Protein Complex ◽  
Coated Vesicles ◽  
Initiation Factor ◽  
Interacting Protein ◽  
Complex Ii ◽  
Transport Vesicles ◽  
Er Exit Sites ◽  
Copii Vesicles

Large coat protein complex II (COPII)-coated vesicles serve to convey the large cargo procollagen I (PC1) from the endoplasmic reticulum (ER). The link between large cargo in the lumen of the ER and modulation of the COPII machinery remains unresolved. TANGO1 is required for PC secretion and interacts with PC and COPII on opposite sides of the ER membrane, but evidence suggests that TANGO1 is retained in the ER, and not included in normal size (<100 nm) COPII vesicles. Here we show that TANGO1 is exported out of the ER in large COPII-coated PC1 carriers, and retrieved back to the ER by the retrograde coat, COPI, mediated by the C-terminal RDEL retrieval sequence of HSP47. TANGO1 is known to target the COPII initiation factor SEC12 to ER exit sites through an interacting protein, cTAGE5. SEC12 is important for the growth of COPII vesicles, but it is not sorted into small budded vesicles. We found both cTAGE5 and SEC12 were exported with TANGO1 in large COPII carriers. In contrast to its exclusion from small transport vesicles, SEC12 was particularly enriched around ER membranes and large COPII carriers that contained PC1. We constructed a split GFP system to recapitulate the targeting of SEC12 to PC1 via the luminal domain of TANGO1. The minimal targeting system enriched SEC12 around PC1 and generated large PC1 carriers. We conclude that TANGO1, cTAGE5, and SEC12 are copacked with PC1 into COPII carriers to increase the size of COPII, thus ensuring the capture of large cargo.

scholarly journals Interaction of Coatomer with Aminoglycoside Antibiotics: Evidence That Coatomer Has at Least Two Dilysine Binding Sites

1997 ◽  
Vol 8 (10) ◽  
pp. 1901-1910 ◽  
Author(s):  
Robert Tod Hudson ◽  
Rockford K. Draper
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Golgi Apparatus ◽  
Binding Sites ◽  
Aminoglycoside Antibiotics ◽  
Carboxyl Terminus ◽  
Amino Groups ◽  
Cell Extracts ◽  
Golgi Membranes ◽  
Lysine Residues

Coatomer is the soluble precursor of the COPI coat (coat protein I) involved in traffic among membranes of the endoplasmic reticulum and the Golgi apparatus. We report herein that neomycin precipitates coatomer from cell extracts and from purified coatomer preparations. Precipitation first increased and then decreased as the neomycin concentration increased, analogous to the precipitation of a polyvalent antigen by divalent antibodies. This suggested that neomycin cross-linked coatomer into large aggregates and implies that coatomer has two or more binding sites for neomycin. A variety of other aminoglycoside antibiotics precipitated coatomer, or if they did not precipitate, they interfered with the ability of neomycin to precipitate. Coatomer is known to interact with a motif (KKXX) containing adjacent lysine residues at the carboxyl terminus of the cytoplasmic domains of some membrane proteins resident in the endoplasmic reticulum. All of the antibiotics that interacted with coatomer contain at least two close amino groups, suggesting that the antibiotics might be interacting with the di-lysine binding site of coatomer. Consistent with this idea, di-lysine itself blocked the interaction of antibiotics with coatomer. Moreover, di-lysine and antibiotics each blocked the coating of Golgi membranes by coatomer. These data suggest that certain aminoglycoside antibiotics interact with di-lysine binding sites on coatomer and that coatomer contains at least two of these di-lysine binding sites.

scholarly journals Dynamics of COPII Vesicles and the Golgi Apparatus in Cultured Nicotiana tabacum BY-2 Cells Provides Evidence for Transient Association of Golgi Stacks with Endoplasmic Reticulum Exit Sites

2005 ◽  
Vol 17 (5) ◽  
pp. 1513-1531 ◽  
Author(s):  
Yao-dong Yang ◽  
Rabab Elamawi ◽  
Julia Bubeck ◽  
Rainer Pepperkok ◽  
Christophe Ritzenthaler ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Nicotiana Tabacum ◽  
Golgi Apparatus ◽  
Copii Vesicles

Tunnels for Protein Export from the Endoplasmic Reticulum

2021 ◽  
Vol 90 (1) ◽  
Author(s):  
I. Raote ◽  
V. Malhotra
Keyword(s):  
Endoplasmic Reticulum ◽  
Coat Protein ◽  
Protein Secretion ◽  
Secretory Pathway ◽  
Protein Export ◽  
Annual Review ◽  
Publication Date ◽  
Early Secretory Pathway ◽  
Copii Vesicles ◽  
Golgi Organization

The functions of coat protein complex II (COPII) coats in cargo packaging and the creation of vesicles at the endoplasmic reticulum are conserved in eukaryotic protein secretion. Standard COPII vesicles, however, cannot handle the secretion of metazoan-specific cargoes such as procollagens, apolipoproteins, and mucins. Metazoans have thus evolved modules centered on proteins like TANGO1 (transport and Golgi organization 1) to engage COPII coats and early secretory pathway membranes to engineer a novel mode of cargo export at the endoplasmic reticulum. Expected final online publication date for the Annual Review of Biochemistry, Volume 90 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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