Ribosome-bound Get4/5 facilitates the capture of tail-anchored proteins by Sgt2 in yeast
| Autor: | Zhang, Y., Laurentiis, E., Bohnsack, K., Wahlig, M., Ranjan, N., Gruseck, S., Hackert, P., Wölfle, T., Rodnina, M., Schwappach, B., Rospert, S. |
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| Rok vydání: | 2020 |
| Předmět: |
Adenosine Triphosphatases
Ribosomal Proteins Saccharomyces cerevisiae Proteins Ubiquitin Science Cell Membrane Membrane Proteins Saccharomyces cerevisiae Peptide Chain Termination Translational Endoplasmic Reticulum Recombinant Proteins Article Mutation Chaperones Guanine Nucleotide Exchange Factors Protein Multimerization Carrier Proteins Ribosomes Signal Recognition Particle Protein Binding |
| Zdroj: | Nature Communications Nature Communications, Vol 12, Iss 1, Pp 1-17 (2021) |
| ISSN: | 2041-1723 |
| Popis: | The guided entry of tail-anchored proteins (GET) pathway assists in the posttranslational delivery of tail-anchored proteins, containing a single C-terminal transmembrane domain, to the ER. Here we uncover how the yeast GET pathway component Get4/5 facilitates capture of tail-anchored proteins by Sgt2, which interacts with tail-anchors and hands them over to the targeting component Get3. Get4/5 binds directly and with high affinity to ribosomes, positions Sgt2 close to the ribosomal tunnel exit, and facilitates the capture of tail-anchored proteins by Sgt2. The contact sites of Get4/5 on the ribosome overlap with those of SRP, the factor mediating cotranslational ER-targeting. Exposure of internal transmembrane domains at the tunnel exit induces high-affinity ribosome binding of SRP, which in turn prevents ribosome binding of Get4/5. In this way, the position of a transmembrane domain within nascent ER-targeted proteins mediates partitioning into either the GET or SRP pathway directly at the ribosomal tunnel exit. The guided entry of tail-anchored proteins (GET) pathway assists in the delivery of such proteins to the ER. Here, the authors reveal that the pathway components Get4/5 probe a region near the ribosomal exit tunnel. Upon emergence of a client protein, Get4/5 recruits Sgt2 and initiates the targeting phase of the pathway. |
| Databáze: | OpenAIRE |
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