A Novel Approach to Recovery of Function of Mutant Proteins by Slowing Down Translation

Anatoli B Meriin,Martin Mense,Jeff D Colbert,Feng Liang,Hermann Bihler,Nava Zaarur,Kenneth L Rock,Michael Y Sherman

doi:10.1074/jbc.m112.397307

Abstract

Protein homeostasis depends on a balance of translation, folding, and degradation. Here, we demonstrate that mild inhibition of translation results in a dramatic and disproportional reduction in production of misfolded polypeptides in mammalian cells, suggesting an improved folding of newly synthesized proteins. Indeed, inhibition of translation elongation, which slightly attenuated levels of a copepod GFP mutant protein, significantly enhanced its function. In contrast, inhibition of translation initiation had minimal effects on copepod GFP folding. On the other hand, mild suppression of either translation elongation or initiation corrected folding defects of the disease-associated cystic fibrosis transmembrane conductance regulator mutant F508del. We propose that modulation of translation can be used as a novel approach to improve overall proteostasis in mammalian cells, as well as functions of disease-associated mutant proteins with folding deficiencies.

Highlights

Current strategies to alleviate protein misfolding include manipulation of chaperones, proteasomes, or autophagy
We propose that modulation of translation can be used as a novel approach to improve overall proteostasis in mammalian cells, as well as functions of disease-associated mutant proteins with folding deficiencies
We found that this process is triggered by the buildup of newly synthesized aberrant proteins [22], which allowed assessing the levels of these species by monitoring aggresome formation

Summary

Introduction

Current strategies to alleviate protein misfolding include manipulation of chaperones, proteasomes, or autophagy. Results: Mild translation inhibition disproportionally blocked production of misfolded proteins and improved mutant CFTR function. Conclusion: Slowing down translation improves folding of newly synthesized proteins in mammalian cells and recovers mutant protein function. Significance: Attenuation of translation could be a novel approach to treatment of protein-misfolding disorders. We demonstrate that mild inhibition of translation results in a dramatic and disproportional reduction in production of misfolded polypeptides in mammalian cells, suggesting an improved folding of newly synthesized proteins. Inhibition of translation elongation, which slightly attenuated levels of a copepod GFP mutant protein, significantly enhanced its function. We propose that modulation of translation can be used as a novel approach to improve overall proteostasis in mammalian cells, as well as functions of disease-associated mutant proteins with folding deficiencies

Methods

Results

Conclusion