Protein Secretion and Vesicle Traffic by Randy Schekman - Part 1: Genetic Dissection of the Secretory Pathway (36:35)

SciVee ◽  
2008 ◽  
Keyword(s):  
Protein Secretion ◽  
Secretory Pathway ◽  
Genetic Dissection ◽  
Vesicle Traffic

Membrane traffic related to endosome dynamics and protein secretion in filamentous fungi

2021 ◽  
Author(s):  
Yujiro Higuchi
Keyword(s):  
Filamentous Fungi ◽  
Protein Secretion ◽  
Secretory Pathway ◽  
Molecular Mechanisms ◽  
Membrane Traffic ◽  
Early Endosome ◽  
Protein Glycosylation ◽  
Hyphal Cell ◽  
Cell Factories ◽  
Membrane Contacts

ABSTRACT In eukaryotic cells, membrane-surrounded organelles are orchestrally organized spatiotemporally under environmental situations. Among such organelles, vesicular transports and membrane contacts occur to communicate each other, so-called membrane traffic. Filamentous fungal cells are highly polarized and thus membrane traffic is developed to have versatile functions. Early endosome (EE) is an endocytic organelle that dynamically exhibits constant long-range motility through the hyphal cell, which is proven to have physiological roles, such as other organelle distribution and signal transduction. Since filamentous fungal cells are also considered as cell factories, to produce valuable proteins extracellularly, molecular mechanisms of secretory pathway including protein glycosylation have been well investigated. In this review, molecular and physiological aspects of membrane traffic especially related to EE dynamics and protein secretion in filamentous fungi are summarized, and perspectives for application are also described.

Investigation of the role of microtubules in protein secretion from lactating mouse mammary epithelial cells

1992 ◽  
Vol 102 (2) ◽  
pp. 239-247 ◽  
Author(s):  
M.E. Rennison ◽  
S.E. Handel ◽  
C.J. Wilde ◽  
R.D. Burgoyne
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Protein Secretion ◽  
Secretory Pathway ◽  
Mammary Epithelial Cells ◽  
Early Stage ◽  
Major Effect ◽  
Vesicle Transport ◽  
Mammary Epithelial ◽  
Mammary Cells

Disruption of microtubules has been shown to reduce protein secretion from lactating mammary epithelial cells. To investigate the involvement of microtubules in the secretory pathway in these cells we have examined the effect of nocodazole on protein secretion from mammary epithelial cells derived from the lactating mouse. Mouse mammary cells have extensive microtubule networks and 85% of their tubulin was in a polymeric form. Treatment with 1 micrograms/ml nocodazole converted most of the tubulin into a soluble form. In a continuous labelling protocol it was found that nocodazole did not interfere with protein synthesis but over a 5 h period secretion was markedly inhibited. To determine whether the inhibition was at the level of early or late stages of the secretory pathway mammary cells were pulse-labelled for 1 h to label protein throughout the secretory pathway before nocodazole treatment. When secretion was subsequently assayed it was found to be slower and only partially inhibited. These findings suggest that the major effect of nocodazole is on an early stage of the secretory pathway and that microtubules normally facilitate vesicle transport to the plasma membrane. An involvement of microtubules in vesicle transport to the plasma membrane is consistent with an observed accumulation of casein vesicles in nocodazole-treated cells. Exocytosis stimulated by the calcium ionophore ionomycin was unaffected by nocodazole treatment. We conclude from these results that the major effect of nocodazole is at an early stage of the secretory pathway, one possible target being casein vesicle biogenesis in the trans-Golgi network.

scholarly journals Brefeldin A inhibits transport of the glycophorin-binding protein from Plasmodium falciparum into the host erythrocyte

1994 ◽  
Vol 300 (3) ◽  
pp. 821-826 ◽  
Author(s):  
J Benting ◽  
D Mattei ◽  
K Lingelbach
Keyword(s):  
Plasmodium Falciparum ◽  
Golgi Apparatus ◽  
Host Cell ◽  
Protein Secretion ◽  
Secretory Pathway ◽  
Binding Protein ◽  
Brefeldin A ◽  
Cell Cytoplasm ◽  
Parasite Cell ◽  
Host Cell Cytoplasm

Plasmodium falciparum, a protozoan parasite of the human erythrocyte, causes the most severe form of malaria. During its intraerythrocytic development, the parasite synthesizes proteins which are exported into the host cell. The compartments involved in the secretory pathway of P. falciparum are still poorly characterized. A Golgi apparatus has not been identified, owing to the lack of specific protein markers and Golgi-specific post-translational modifications in the parasite. The fungal metabolite brefeldin A (BFA) is known to inhibit protein secretion in higher eukaryotes by disrupting the integrity of the Golgi apparatus. We have used the parasite-encoded glycophorin-binding protein (GBP), a soluble protein found in the host cell cytoplasm, as a marker to investigate the effects of BFA on protein secretion in the intracellular parasite. In the presence of BFA, GBP was not transported into the erythrocyte, but remained inside the parasite cell. The effect caused by BFA was reversible, and the protein could be chased into the host cell cytoplasm within 30 min. Transport of GBP from the BFA-sensitive site into the host cell did not require protein synthesis. Similar observations were made when infected erythrocytes were incubated at 15 degrees C. Incubation at 20 degrees C resulted in a reduction rather than a complete block of protein export. The relevance of our findings to the identification of compartments involved in protein secretion from the parasite cell is discussed.

scholarly journals Intracellular Retention of the Corticotrophin-releasing Hormone (CRH) Precursor Within COS-7 Cells

1998 ◽  
Vol 46 (10) ◽  
pp. 1193-1197 ◽  
Author(s):  
Marcelo J. Perone ◽  
Simon Windeatt ◽  
Ewan Morrison ◽  
Andy Shering ◽  
Peter Tomasec ◽  
...  
Keyword(s):  
Amino Acid ◽  
Golgi Apparatus ◽  
Amino Acid Sequence ◽  
Protein Secretion ◽  
Intracellular Trafficking ◽  
Secretory Pathway ◽  
Intracellular Localization ◽  
Primary Amino Acid Sequence ◽  
Releasing Hormone ◽  
Primary Amino

We investigated the intracellular localization of CRH in transiently transfected COS-7 cells expressing the full-length rat corticotropin-releasing hormone (CRH) precursor cDNA. CRH synthesized by transfected COS-7 cells is mainly stored intracellularly. In contrast, CHO-K1 cells expressing the same CRH precursor stored and released equal amounts of immunoreactive (IR)-CRH. Ultrastructural analysis revealed that CRH is stored in electron-dense aggregates in the RER of transiently transfected COS-7 cells and does not migrate into the Golgi apparatus. On the basis of the different intracellular localization, storage, and release of CRH in COS-7 and CHO-K1 cells, we hypothesize that the intracellular trafficking of CRH within the constitutive secretory pathway for protein secretion not only depends on its primary amino acid sequence but might also be influenced by intracellular conditions or factors.

The Secretory Pathway for Milk Protein Secretion and Its Regulation

1995 ◽  
pp. 253-263
Author(s):  
Robert D. Burgoyne ◽  
Susan E. Handel ◽  
Allan W. Sudlow ◽  
Mark D. Turner ◽  
Satish Kumar ◽  
...  
Keyword(s):  
Protein Secretion ◽  
Milk Protein ◽  
Secretory Pathway

scholarly journals Divergence of Eukaryotic Secretory Components: the Candida albicans Homolog of the Saccharomyces cerevisiae Sec20 Protein Is N Terminally Truncated, and Its Levels Determine Antifungal Drug Resistance and Growth

2001 ◽  
Vol 183 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Yvonne Weber ◽  
Uwe J. Santore ◽  
Joachim F. Ernst ◽  
Rolf K. Swoboda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Transcriptional Control ◽  
Secretory Pathway ◽  
Sodium Dodecyl ◽  
Fungal Species ◽  
Gene Encoding ◽  
Vesicle Traffic ◽  
Antifungal Drug Resistance ◽  
And Function

ABSTRACT Sec20p is a component of the yeast Saccharomyces cerevisiae secretory pathway that does not have a close homolog in higher eukaryotic cells. To verify the function of Sec20p in other fungal species, we characterized the gene encoding a Sec20p homolog in the human fungal pathogen Candida albicans. The deduced protein has 27% identity with, but is missing about 100 N-terminal residues compared to S. cerevisiae Sec20p, which is part of the cytoplasmic tail interacting with the cytoplasmic protein Tip20p. Because a strain lacking both C. albicans SEC20alleles could not be constructed, we placed SEC20 under transcriptional control of two regulatable promoters, MET3pand PCK1p. Repression of SEC20 expression in these strains prevented (MET3p-SEC20 allele) or retarded (PCK1p-SEC20 allele) growth and led to the appearance of extensive intracellular membranes, which frequently formed stacks. Reduced SEC20 expression in the PCK1p-SEC20strain did not affect morphogenesis but led to a series of hypersensitivity phenotypes including supersensitivity to aminoglycoside antibiotics, to nystatin, to sodium dodecyl sulfate, and to cell wall inhibitors. These results demonstrate the occurrence and function of Sec20p in a fungal species other than S. cerevisiae, but the lack of the N-terminal domain and the apparent absence of a close TIP20 homolog in the C. albicans genome also indicate a considerable diversity in mechanisms of retrograde vesicle traffic in eukaryotes.

scholarly journals Stimulation of immunity-linked genes by membrane disruption is linked to Golgi function and the ARF-1 GTPase

2021 ◽  
Author(s):  
Christofer M Welsh ◽  
Lorissa J Smulan ◽  
Matthew J Fanelli ◽  
Dominuque S Lui ◽  
Amy Karol Walker
Keyword(s):  
Immune Response ◽  
Stress Response ◽  
Protein Secretion ◽  
Secretory Pathway ◽  
Metabolic Changes ◽  
Membrane Disruption ◽  
Intrinsic Cues ◽  
Lipid Imbalance ◽  
Adp Ribosylation Factor ◽  
Stimulation Of

Immune-linked genes (ILGs) are activated in response to pathogens but can also be activated by lipid imbalance. Why pathogen attack and metabolic changes both impact ILG activation is unclear. Organelles in the secretory pathway have distinct protein and lipid components and genetically separable stress programs. These stress pathways activate restorative transcriptional programs when lipid ratios become unbalanced or during dysregulated protein folding and trafficking. We find that ILGs are specifically activated when membrane phosphatidylcholine ratios change in the secretory pathway. Consistent with this result, disruption of Golgi function in mutations targeting the ADP-ribosylation factor ARF-1 also activates ILG expression. Since increased protein secretion is altered by metabolic changes and pathogen responses, our data argue that ILG upregulation is a conserved, coordinated response to changes in trafficking resulting from intrinsic cues (lipid changes) or extrinsic stimulation (during the immune response). These findings uncover important and previously unexplored links between metabolism and the stress response.

scholarly journals Genome-scale reconstructions of the mammalian secretory pathway predict metabolic costs and limitations of protein secretion

2018 ◽  
Author(s):  
Jahir M. Gutierrez ◽  
Amir Feizi ◽  
Shangzhong Li ◽  
Thomas B. Kallehauge ◽  
Hooman Hefzi ◽  
...  
Keyword(s):  
Protein Secretion ◽  
Mammalian Cells ◽  
Secretory Pathway ◽  
Chinese Hamster ◽  
Selection Marker ◽  
Secretory Cells ◽  
Systems Biotechnology ◽  
Host Cell Proteins ◽  
Metabolic Costs ◽  
Genome Scale

AbstractIn mammalian cells, >25% of synthesized proteins are exported through the secretory pathway. The pathway complexity, however, obfuscates its impact on the secretion of different proteins. Unraveling its impact on diverse proteins is particularly important for biopharmaceutical production. Here we delineate the core secretory pathway functions and integrate them with genome-scale metabolic reconstructions of human, mouse, and Chinese hamster cells. The resulting reconstructions enable the computation of energetic costs and machinery demands of each secreted protein. By integrating additional omics data, we find that highly secretory cells have adapted to reduce expression and secretion of other expensive host cell proteins. Furthermore, we predict metabolic costs and maximum productivities of biotherapeutic proteins and identify protein features that most significantly impact protein secretion. Finally, the model successfully predicts the increase in secretion of a monoclonal antibody after silencing a highly expressed selection marker. This work represents a knowledgebase of the mammalian secretory pathway that serves as a novel tool for systems biotechnology.

scholarly journals Natural products as modulators of eukaryotic protein secretion

2020 ◽  
Vol 37 (5) ◽  
pp. 717-736 ◽  
Author(s):  
Hendrik Luesch ◽  
Ville O. Paavilainen
Keyword(s):  
Natural Products ◽  
Protein Secretion ◽  
Secretory Pathway ◽  
Therapeutic Potential ◽  
Eukaryotic Protein ◽  
Mammalian Protein

This highlight reviews functions and therapeutic potential of diverse natural products that target different components of the mammalian protein secretory pathway.

scholarly journals Genome-scale reconstructions of the mammalian secretory pathway predict metabolic costs and limitations of protein secretion

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jahir M. Gutierrez ◽  
Amir Feizi ◽  
Shangzhong Li ◽  
Thomas B. Kallehauge ◽  
Hooman Hefzi ◽  
...  
Keyword(s):  
Protein Secretion ◽  
Mammalian Cells ◽  
Secretory Pathway ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Selection Marker ◽  
Secretory Cells ◽  
Systems Biotechnology ◽  
Metabolic Costs ◽  
Genome Scale

AbstractIn mammalian cells, >25% of synthesized proteins are exported through the secretory pathway. The pathway complexity, however, obfuscates its impact on the secretion of different proteins. Unraveling its impact on diverse proteins is particularly important for biopharmaceutical production. Here we delineate the core secretory pathway functions and integrate them with genome-scale metabolic reconstructions of human, mouse, and Chinese hamster ovary cells. The resulting reconstructions enable the computation of energetic costs and machinery demands of each secreted protein. By integrating additional omics data, we find that highly secretory cells have adapted to reduce expression and secretion of other expensive host cell proteins. Furthermore, we predict metabolic costs and maximum productivities of biotherapeutic proteins and identify protein features that most significantly impact protein secretion. Finally, the model successfully predicts the increase in secretion of a monoclonal antibody after silencing a highly expressed selection marker. This work represents a knowledgebase of the mammalian secretory pathway that serves as a novel tool for systems biotechnology.

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