scholarly journals Dynamics of Co-translational Membrane Protein Integration and Translocation via the Sec Translocon

2020 ◽  
Vol 142 (12) ◽  
pp. 5449-5460
Author(s):  
Michiel J. M. Niesen ◽  
Matthew H. Zimmer ◽  
Thomas F. Miller
Keyword(s):  
Membrane Protein ◽  
Sec Translocon

scholarly journals In vitro membrane protein synthesis inside Sec translocon-reconstituted cell-sized liposomes

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Naoki Ohta ◽  
Yasuhiko Kato ◽  
Hajime Watanabe ◽  
Hirotada Mori ◽  
Tomoaki Matsuura
Keyword(s):  
Protein Synthesis ◽  
Membrane Protein ◽  
Sec Translocon

scholarly journals The Escherichia coli Membrane Protein Insertase YidC Assists in the Biogenesis of Penicillin Binding Proteins

2015 ◽  
Vol 197 (8) ◽  
pp. 1444-1450 ◽  
Author(s):  
Anabela de Sousa Borges ◽  
Jeanine de Keyzer ◽  
Arnold J. M. Driessen ◽  
Dirk-Jan Scheffers
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Binding Proteins ◽  
Protein Complexes ◽  
Specific Cell ◽  
Similar Reduction ◽  
Penicillin Binding Proteins ◽  
Membrane Protein Complexes ◽  
Sec Translocon

ABSTRACTMembrane proteins need to be properly inserted and folded in the membrane in order to perform a range of activities that are essential for the survival of bacteria. The Sec translocon and the YidC insertase are responsible for the insertion of the majority of proteins into the cytoplasmic membrane. YidC can act in combination with the Sec translocon in the insertion and folding of membrane proteins. However, YidC also functions as an insertase independently of the Sec translocon for so-called YidC-only substrates. In addition, YidC can act as a foldase and promote the proper assembly of membrane protein complexes. Here, we investigate the effect ofEscherichia coliYidC depletion on the assembly of penicillin binding proteins (PBPs), which are involved in cell wall synthesis. YidC depletion does not affect the total amount of the specific cell division PBP3 (FtsI) in the membrane, but the amount of active PBP3, as assessed by substrate binding, is reduced 2-fold. A similar reduction in the amount of active PBP2 was observed, while the levels of active PBP1A/1B and PBP5 were essentially similar. PBP1B and PBP3 disappeared from higher-Mwbands upon YidC depletion, indicating that YidC might play a role in PBP complex formation. Taken together, our results suggest that the foldase activity of YidC can extend to the periplasmic domains of membrane proteins.IMPORTANCEThis study addresses the role of the membrane protein insertase YidC in the biogenesis of penicillin binding proteins (PBPs). PBPs are proteins containing one transmembrane segment and a large periplasmic or extracellular domain, which are involved in peptidoglycan synthesis. We observe that in the absence of YidC, two critical PBPs are not correctly folded even though the total amount of protein in the membrane is not affected. Our findings extend the function of YidC as a foldase for membrane protein (complexes) to periplasmic domains of membrane proteins.

scholarly journals Determinants of Multispanning Membrane Protein Integration Mediated by the Sec Translocon

2016 ◽  
Vol 110 (3) ◽  
pp. 56a-57a
Author(s):  
Reid C. Van Lehn ◽  
Bin Zhang ◽  
Thomas F. Miller
Keyword(s):  
Membrane Protein ◽  
Sec Translocon

scholarly journals Coarse-Grained Modeling of Membrane Protein Integration via the Sec Translocon

2016 ◽  
Vol 110 (3) ◽  
pp. 56a
Author(s):  
Michiel J.M. Niesen ◽  
Connie Y. Wang ◽  
Thomas F. Miller
Keyword(s):  
Membrane Protein ◽  
Coarse Grained ◽  
Sec Translocon

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.

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