scholarly journals Study on the interaction mechanism of phospholipid imbalance and endoplasmic reticulum protein secretion imbalance in Aspergillus niger

2021 ◽  
Vol 1863 (3) ◽  
pp. 183530
Author(s):  
Hongzhi Dong ◽  
Bin Wang ◽  
Li Pan
2008 ◽  
Vol 19 (8) ◽  
pp. 3442-3453 ◽  
Author(s):  
Javier Calvo-Garrido ◽  
Sergio Carilla-Latorre ◽  
Francisco Lázaro-Diéguez ◽  
Gustavo Egea ◽  
Ricardo Escalante

Vacuole membrane protein 1 (Vmp1) is membrane protein of unknown molecular function that has been associated with pancreatitis and cancer. The social amoeba Dictyostelium discoideum has a vmp1-related gene that we identified previously in a functional genomic study. Loss-of-function of this gene leads to a severe phenotype that compromises Dictyostelium growth and development. The expression of mammalian Vmp1 in a vmp1− Dictyostelium mutant complemented the phenotype, suggesting a functional conservation of the protein among evolutionarily distant species and highlights Dictyostelium as a valid experimental system to address the function of this gene. Dictyostelium Vmp1 is an endoplasmic reticulum protein necessary for the integrity of this organelle. Cells deficient in Vmp1 display pleiotropic defects in the secretory pathway and organelle biogenesis. The contractile vacuole, which is necessary to survive under hypoosmotic conditions, is not functional in the mutant. The structure of the Golgi apparatus, the function of the endocytic pathway and conventional protein secretion are also affected in these cells. Transmission electron microscopy of vmp1− cells showed the accumulation of autophagic features that suggests a role of Vmp1 in macroautophagy. In addition to these defects observed at the vegetative stage, the onset of multicellular development and early developmental gene expression are also compromised.


Author(s):  
James R. Gaylor ◽  
Fredda Schafer ◽  
Robert E. Nordquist

Several theories on the origin of the melanosome exist. These include the Golgi origin theory, in which a tyrosinase-rich protein is "packaged" by the Golgi apparatus, thus forming the early form of the melanosome. A second theory postulates a mitochondrial origin of melanosomes. Its author contends that the melanosome is a modified mitochondria which acquires melanin during its development. A third theory states that a pre-melanosome is formed in the smooth or rough endoplasmic reticulum. Protein aggregation is suggested by one author as a possible source of the melanosome. This fourth theory postulates that the melanosome originates when the protein products of several genetic loci aggregate in the cytoplasm of the melanocyte. It is this protein matrix on which the melanin is deposited. It was with these theories in mind that this project was undertaken.


1993 ◽  
Vol 6 (5) ◽  
pp. 609-615 ◽  
Author(s):  
Neil R. Pumford ◽  
Brian M. Martin ◽  
David Thomassen ◽  
Jennifer A. Burris ◽  
J. Gerald Kenna ◽  
...  

2001 ◽  
Vol 114 (24) ◽  
pp. 4629-4635
Author(s):  
Michel J. Massaad ◽  
Annette Herscovics

The α1,2-mannosidase Mns1p involved in the N-glycosidic pathway in Saccharomyces cerevisiae is a type II membrane protein of the endoplasmic reticulum. The localization of Mns1p depends on retrieval from the Golgi through a mechanism that involves Rer1p. A chimera consisting of the transmembrane domain of Mns1p fused to the catalytic domain of the Golgi α1,2-mannosyltransferase Kre2p was localized in the endoplasmic reticulum of Δpep4 cells and in the vacuoles of rer1/Δpep4 by indirect immunofluorescence. The split-ubiquitin system was used to determine if there is an interaction between Mns1p and Rer1p in vivo. Co-expression of NubG-Mns1p and Rer1p-Cub-protein A-lexA-VP16 in L40 yeast cells resulted in cleavage of the reporter molecule, protein A-lexA-VP16, detected by western blot analysis and by expression of β-galactosidase activity. Sec12p, another endoplasmic reticulum protein that depends on Rer1p for its localization, also interacted with Rer1p using the split-ubiquitin assay, whereas the endoplasmic reticulum protein Ost1p showed no interaction. A weak interaction was observed between Alg5p and Rer1p. These results demonstrate that the transmembrane domain of Mns1p is sufficient for Rer1p-dependent endoplasmic reticulum localization and that Mns1p and Rer1p interact. Furthermore, the split-ubiquitin system demonstrates that the C-terminal of Rer1p is in the cytosol.


eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Cristina Nogueira ◽  
Patrik Erlmann ◽  
Julien Villeneuve ◽  
António JM Santos ◽  
Emma Martínez-Alonso ◽  
...  

TANGO1 binds and exports Procollagen VII from the endoplasmic reticulum (ER). In this study, we report a connection between the cytoplasmic domain of TANGO1 and SLY1, a protein that is required for membrane fusion. Knockdown of SLY1 by siRNA arrested Procollagen VII in the ER without affecting the recruitment of COPII components, general protein secretion, and retrograde transport of the KDEL-containing protein BIP, and ERGIC53. SLY1 is known to interact with the ER-specific SNARE proteins Syntaxin 17 and 18, however only Syntaxin 18 was required for Procollagen VII export. Neither SLY1 nor Syntaxin 18 was required for the export of the equally bulky Procollagen I from the ER. Altogether, these findings reveal the sorting of bulky collagen family members by TANGO1 at the ER and highlight the existence of different export pathways for secretory cargoes one of which is mediated by the specific SNARE complex containing SLY1 and Syntaxin 18.


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