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Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells

Various landmark studies have revealed structures and functions of the Sec61/SecY complex in all domains of live demonstrating the conserved nature of this ancestral protein translocase. While the bacterial homolog of the Sec61 complex resides in the plasma membrane, the eukaryotic counterpart manag...

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Autores principales: Sicking, Mark, Jung, Martin, Lang, Sven
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8508666/
https://www.ncbi.nlm.nih.gov/pubmed/34638699
http://dx.doi.org/10.3390/ijms221910358
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author Sicking, Mark
Jung, Martin
Lang, Sven
author_facet Sicking, Mark
Jung, Martin
Lang, Sven
author_sort Sicking, Mark
collection PubMed
description Various landmark studies have revealed structures and functions of the Sec61/SecY complex in all domains of live demonstrating the conserved nature of this ancestral protein translocase. While the bacterial homolog of the Sec61 complex resides in the plasma membrane, the eukaryotic counterpart manages the transfer of precursor proteins into or across the membrane of the endoplasmic reticulum (ER). Sec61 complexes are accompanied by a set of dynamically recruited auxiliary proteins assisting the transport of certain precursor polypeptides. TRAP and Sec62/Sec63 are two auxiliary protein complexes in mammalian cells that have been characterized by structural and biochemical methods. Using these ER membrane protein complexes for our proof-of-concept study, we aimed to detect interactions of membrane proteins in living mammalian cells under physiological conditions. Bimolecular luminescence complementation and competition was used to demonstrate multiple protein–protein interactions of different topological layouts. In addition to the interaction of the soluble catalytic and regulatory subunits of the cytosolic protein kinase A, we detected interactions of ER membrane proteins that either belong to the same multimeric protein complex (intra-complex interactions: Sec61α–Sec61β, TRAPα–TRAPβ) or protein complexes in juxtaposition (inter-complex interactions: Sec61α–TRAPα, Sec61α–Sec63, and Sec61β–Sec63). In the process, we established further control elements like synthetic peptide complementation for expression profiling of fusion constructs and protease-mediated reporter degradation demonstrating the cytosolic localization of a reporter complementation. Ease of use and flexibility of the approach presented here will spur further research regarding the dynamics of protein–protein interactions in response to changing cellular conditions in living cells.
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spelling pubmed-85086662021-10-13 Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells Sicking, Mark Jung, Martin Lang, Sven Int J Mol Sci Article Various landmark studies have revealed structures and functions of the Sec61/SecY complex in all domains of live demonstrating the conserved nature of this ancestral protein translocase. While the bacterial homolog of the Sec61 complex resides in the plasma membrane, the eukaryotic counterpart manages the transfer of precursor proteins into or across the membrane of the endoplasmic reticulum (ER). Sec61 complexes are accompanied by a set of dynamically recruited auxiliary proteins assisting the transport of certain precursor polypeptides. TRAP and Sec62/Sec63 are two auxiliary protein complexes in mammalian cells that have been characterized by structural and biochemical methods. Using these ER membrane protein complexes for our proof-of-concept study, we aimed to detect interactions of membrane proteins in living mammalian cells under physiological conditions. Bimolecular luminescence complementation and competition was used to demonstrate multiple protein–protein interactions of different topological layouts. In addition to the interaction of the soluble catalytic and regulatory subunits of the cytosolic protein kinase A, we detected interactions of ER membrane proteins that either belong to the same multimeric protein complex (intra-complex interactions: Sec61α–Sec61β, TRAPα–TRAPβ) or protein complexes in juxtaposition (inter-complex interactions: Sec61α–TRAPα, Sec61α–Sec63, and Sec61β–Sec63). In the process, we established further control elements like synthetic peptide complementation for expression profiling of fusion constructs and protease-mediated reporter degradation demonstrating the cytosolic localization of a reporter complementation. Ease of use and flexibility of the approach presented here will spur further research regarding the dynamics of protein–protein interactions in response to changing cellular conditions in living cells. MDPI 2021-09-26 /pmc/articles/PMC8508666/ /pubmed/34638699 http://dx.doi.org/10.3390/ijms221910358 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Sicking, Mark
Jung, Martin
Lang, Sven
Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells
title Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells
title_full Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells
title_fullStr Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells
title_full_unstemmed Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells
title_short Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells
title_sort lights, camera, interaction: studying protein–protein interactions of the er protein translocase in living cells
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8508666/
https://www.ncbi.nlm.nih.gov/pubmed/34638699
http://dx.doi.org/10.3390/ijms221910358
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