scholarly journals Short transmembrane domains with high-volume exoplasmic halves determine retention of Type II membrane proteins in the Golgi complex

2013 ◽  
Vol 126 (23) ◽  
pp. 5344-5349 ◽  
Author(s):  
R. Quiroga ◽  
A. Trenchi ◽  
A. Gonzalez Montoro ◽  
J. Valdez Taubas ◽  
H. J. F. Maccioni
Keyword(s):  
Membrane Proteins ◽  
Golgi Complex ◽  
High Volume ◽  
Transmembrane Domains ◽  
Type Ii

scholarly journals Segregation in the Golgi complex precedes export of endolysosomal proteins in distinct transport carriers

2017 ◽  
Vol 216 (12) ◽  
pp. 4141-4151 ◽  
Author(s):  
Yu Chen ◽  
David C. Gershlick ◽  
Sang Yoon Park ◽  
Juan S. Bonifacino
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Golgi Complex ◽  
Adaptor Proteins ◽  
Transmembrane Domains ◽  
The Other ◽  
Present Evidence ◽  
Sorting Signals ◽  
Vesicular Carriers ◽  
Classical Models

Biosynthetic sorting of newly synthesized transmembrane cargos to endosomes and lysosomes is thought to occur at the TGN through recognition of sorting signals in the cytosolic tails of the cargos by adaptor proteins, leading to cargo packaging into coated vesicles destined for the endolysosomal system. Here we present evidence for a different mechanism in which two sets of endolysosomal proteins undergo early segregation to distinct domains of the Golgi complex by virtue of the proteins’ luminal and transmembrane domains. Proteins in one Golgi domain exit into predominantly vesicular carriers by interaction of sorting signals with adaptor proteins, but proteins in the other domain exit into predominantly tubular carriers shared with plasma membrane proteins, independently of signal–adaptor interactions. These findings demonstrate that sorting of endolysosomal proteins begins at an earlier stage and involves mechanisms that partly differ from those described by classical models.

scholarly journals Evidence that the algI/algJ Gene Cassette, Required for O Acetylation of Pseudomonas aeruginosa Alginate, Evolved by Lateral Gene Transfer

2004 ◽  
Vol 186 (14) ◽  
pp. 4759-4773 ◽  
Author(s):  
Michael J. Franklin ◽  
Stephanie A. Douthit ◽  
Marcella A. McClure
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gene Transfer ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Lateral Gene Transfer ◽  
Transmembrane Domains ◽  
Periplasmic Protein ◽  
Type Ii ◽  
Acetyl Group ◽  
Type Ii Membrane Protein

ABSTRACT Pseudomonas aeruginosa strains, isolated from chronically infected patients with cystic fibrosis, produce the O-acetylated extracellular polysaccharide, alginate, giving these strains a mucoid phenotype. O acetylation of alginate plays an important role in the ability of mucoid P. aeruginosa to form biofilms and to resist complement-mediated phagocytosis. The O-acetylation process is complex, requiring a protein with seven transmembrane domains (AlgI), a type II membrane protein (AlgJ), and a periplasmic protein (AlgF). The cellular localization of these proteins suggests a model wherein alginate is modified at the polymer level after the transport of O-acetyl groups to the periplasm. Here, we demonstrate that this mechanism for polysaccharide esterification may be common among bacteria, since AlgI homologs linked to type II membrane proteins are found in a variety of gram-positive and gram-negative bacteria. In some cases, genes for these homologs have been incorporated into polysaccharide biosynthetic operons other than for alginate biosynthesis. The phylogenies of AlgI do not correlate with the phylogeny of the host bacteria, based on 16S rRNA analysis. The algI homologs and the gene for their adjacent type II membrane protein present a mosaic pattern of gene arrangement, suggesting that individual components of the multigene cassette, as well as the entire cassette, evolved by lateral gene transfer. AlgJ and the other type II membrane proteins, although more diverged than AlgI, contain conserved motifs, including a motif surrounding a highly conserved histidine residue, which is required for alginate O-acetylation activity by AlgJ. The AlgI homologs also contain an ordered series of motifs that included conserved amino acid residues in the cytoplasmic domain CD-4; the transmembrane domains TM-C, TM-D, and TM-E; and the periplasmic domain PD-3. Site-directed mutagenesis studies were used to identify amino acids important for alginate O-acetylation activity, including those likely required for (i) the interaction of AlgI with the O-acetyl precursor in the cytoplasm, (ii) the export of the O-acetyl group across the cytoplasmic membrane, and (iii) the transfer of the O-acetyl group to a periplasmic protein or to alginate. These results indicate that AlgI belongs to a family of membrane proteins required for modification of polysaccharides and that a mechanism requiring an AlgI homolog and a type II membrane protein has evolved by lateral gene transfer for the esterification of many bacterial extracellular polysaccharides.

Prediction of Golgi Type II membrane proteins based on their transmembrane domains

2002 ◽  
Vol 18 (8) ◽  
pp. 1109-1115 ◽  
Author(s):  
Z. Yuan ◽  
R. D. Teasdale
Keyword(s):  
Membrane Proteins ◽  
Transmembrane Domains ◽  
Type Ii

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

scholarly journals There is no correlation between a delayed gastric conduit emptying and the occurrence of an anastomotic leakage after Ivor-Lewis esophagectomy

2022 ◽  
Author(s):  
Benjamin Babic ◽  
Lars Mortimer Schiffmann ◽  
Hans Friedrich Fuchs ◽  
Dolores Thea Mueller ◽  
Thomas Schmidt ◽  
...  
Keyword(s):  
Anastomotic Leakage ◽  
High Volume ◽  
Gastric Conduit ◽  
Common Finding ◽  
Type Ii ◽  
Ivor Lewis ◽  
Stapling Device ◽  
Ivor Lewis Esophagectomy ◽  
Cervical Reconstruction ◽  
Prolonged Hospital

Abstract Introduction Esophagectomy is the gold standard in the surgical therapy of esophageal cancer. It is either performed thoracoabdominal with a intrathoracic anastomosis or in proximal cancers with a three-incision esophagectomy and cervical reconstruction. Delayed gastric conduit emptying (DGCE) is the most common functional postoperative disorder after Ivor-Lewis esophagectomy (IL). Pneumonia is significantly more often in patients with DGCE. It remains unclear if DGCE anastomotic leakage (AL) is associated. Aim of our study is to analyze, if AL is more likely to happen in patients with a DGCE. Patients and methods 816 patients were included. All patients have had an IL due to esophageal/esophagogastric-junction cancer between 2013 and 2018 in our center. Intrathoracic esophagogastric end-to-side anastomosis was performed with a circular stapling device. The collective has been divided in two groups depending on the occurrence of DGCE. The diagnosis DGCE was determined by clinical and radiologic criteria in accordance with current international expert consensus. Results 27.7% of all patients suffered from DGCE postoperatively. Female patients had a significantly higher chance to suffer from DGCE than male patients (34.4% vs. 26.2% vs., p = 0.040). Pneumonia was more common in patients with DGCE (13.7% vs. 8.5%, p = 0.025), furthermore hospitalization was longer in DGCE patients (median 17 days vs. 14d, p < 0.001). There was no difference in the rate of type II anastomotic leakage, (5.8% in both groups DGCE). All patients with ECCG type II AL (n = 47; 5.8%) were treated successfully by endoluminal/endoscopic therapy. The subgroup analysis showed that ASA ≥ III (7.6% vs. 4.4%, p = 0.05) and the histology squamous cell carcinoma (9.8% vs. 4.7%, p = 0.01) were independent risk factors for the occurrence of an AL. Conclusion Our study confirms that DGCE after IL is a common finding in a standardized collective of patients in a high-volume center. This functional disorder is associated with a higher rate of pneumonia and a prolonged hospital stay. Still, there is no association between DGCE and the occurrence of an AL after esophagectomy. The hypothesis, that an DGCE results in a higher pressure on the anastomosis and therefore to an AL in consequence, can be refuted. DGCE is not a pathogenetic factor for an AL.

scholarly journals Cargo induces retromer-mediated membrane remodeling on membranes

2018 ◽  
Vol 29 (22) ◽  
pp. 2709-2719 ◽  
Author(s):  
Latha Kallur Purushothaman ◽  
Christian Ungermann
Keyword(s):  
Plasma Membrane ◽  
Simple Model ◽  
Membrane Proteins ◽  
Golgi Complex ◽  
Exact Order ◽  
Membrane Remodeling ◽  
Sorting Nexin ◽  
Low Concentrations ◽  
Sorting Station ◽  
Specific Trigger

Endosomes serve as a central sorting station of lipids and proteins that arrive via vesicular carrier from the plasma membrane and the Golgi complex. At the endosome, retromer complexes sort selected receptors and membrane proteins into tubules or vesicles that bud off the endosome. The mature endosome finally fuses with the lysosome. Retromer complexes consist of a cargo selection complex (CSC) and a membrane remodeling part (sorting nexin [SNX]-Bin/amphiphysin/Rvs [BAR], or Snx3 in yeast) and different assemblies of retromer mediate recycling of different cargoes. Due to this complexity, the exact order of events that results in carrier formation is not yet understood. Here, we reconstituted this process on giant unilamellar vesicles together with purified retromer complexes from yeast and selected cargoes. Our data reveal that the membrane remodeling activity of both Snx3 and the SNX-BAR complex is strongly reduced at low concentrations, which can be reactivated by CSC. At even lower concentrations, these complexes still associate with membranes, but only remodel membranes in the presence of their specific cargoes. Our data thus favor a simple model, where cargo functions as a specific trigger of retromer-mediated sorting on endosomes.

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