CaltechAUTHORS
  A Caltech Library Service

Co-translational Targeting by Signal Recognition Particle Activates Only after Cytosolic Exposure of Signal Sequence

Hsieh, Hao Hsuan and Shan, Shu-ou (2018) Co-translational Targeting by Signal Recognition Particle Activates Only after Cytosolic Exposure of Signal Sequence. Biophysical Journal, 114 (3). 69a. ISSN 0006-3495. http://resolver.caltech.edu/CaltechAUTHORS:20180510-112234591

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20180510-112234591

Abstract

Signal recognition particle (SRP) and its receptor (SR) co-translationally target membrane and secretory proteins to membrane specifically and efficiently through multiple layers of regulation. Differential SRP binding to ribosome, SRP-SR association rate, and GTP hydrolysis ensure specificity for substrate over non-substrate. However, there is a debate on whether SRP interacts with its substrate when a target sequence is still buried inside ribosome exit tunnel during the early stage of translation. Previous studies, which only focus on SRP binding to ribosome, produce contradictory results. In this study, we examine the full picture of SRP's multiple layers of regulation at each translation intermediate carrying increasing length of nascent chain. FRET-based SRP-ribosome binding affinity assay and fluorescence detected SRP-SR association rate measurement give the formation of key intermediates in SRP targeting cycle as a function of nascent chain length. Both parameters differ for more than two orders of magnitude between N-terminal and full exposure of targeting sequence from the end of ribosome exit tunnel. Such discrimination is comparable to the difference between substrate and non-substrate. Using e. coli as a model system, our results show that SRP targets its substrate exclusively after the emergence of a transmembrane domain or signal sequence from ribosome exit tunnel.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1016/j.bpj.2017.11.425DOIArticle
ORCID:
AuthorORCID
Shan, Shu-ou0000-0002-6526-1733
Additional Information:© 2018 Elsevier Inc. Available online 6 February 2018.
Record Number:CaltechAUTHORS:20180510-112234591
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20180510-112234591
Official Citation:Co-translational Targeting by Signal Recognition Particle Activates Only after Cytosolic Exposure of Signal Sequence Hsuan Hsieh, Hao et al. Biophysical Journal , Volume 114 , Issue 3 , 69a
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:86336
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:10 May 2018 20:32
Last Modified:10 May 2018 20:32

Repository Staff Only: item control page