Sbp1 modulates translation of Pab1 mRNA in a poly(A)- and RGG-dependent manner
- ↵* Corresponding author; email: hjin{at}illinois.edu
Abstract
RNA-binding protein Sbp1 facilitates the decapping pathway in mRNA metabolism and inhibits global mRNA translation by an unclear mechanism. Here we report molecular interactions responsible for Sbp1-mediated translation inhibition of mRNA encoding the polyadenosine-binding protein (Pab1), an essential translation factor that stimulates mRNA translation and inhibits mRNA decapping in eukaryotic cells. We demonstrate that the two distal RRMs of Sbp1 bind to the poly(A)-sequence in the 5′ UTR of the Pab1 mRNA specifically and cooperatively while the central RGG domain of the protein interacts directly with Pab1. Furthermore, methylation of arginines in the RGG doamin abolishes the protein-protein interaction and the inhibitory effect of Sbp1 on translation initiation of Pab1 mRNA. Based on these results, the underlying mechanism for Sbp1-specific translational regulation is proposed. The functional differences of Sbp1 and RGG repeats alone on transcript-specific translation were observed, and a comparison of the results suggests importance of remodeling the 5′ UTR by RNA-binding proteins in mRNA translation.
Keywords
- Received June 16, 2017.
- Accepted September 29, 2017.
- Published by Cold Spring Harbor Laboratory Press for the RNA Society
This article, published in RNA, is available under a Creative Commons License (Attribution 4.0 International), as described at http://creativecommons.org/licenses/by/4.0/.
