Arginine methylation promotes translation repression activity of eIF4G-binding protein, Scd6

Poornima, Gopalakrishna and Shah, Shanaya and Vignesh, Venkadasubramanian and Parker, Roy and Rajyaguru, Purusharth I (2016) Arginine methylation promotes translation repression activity of eIF4G-binding protein, Scd6. In: NUCLEIC ACIDS RESEARCH, 44 (19). pp. 9358-9368.

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Abstract

Regulation of translation plays a critical role in determining mRNA fate. A new role was recently reported for a subset of RGG-motif proteins in repressing translation initiation by binding eIF4G1. However the signaling mechanism(s) that leads to spatial and temporal regulation of repression activity of RGG-motif proteins remains unknown. Here we report the role of arginine methylation in regulation of repression activity of Scd6, a conserved RGG-motif protein. We demonstrate that Scd6 gets arginine methylated at its RGG-motif and Hmt1 plays an important role in its methylation. We identify specific methylated arginine residues in the Scd6 RGG-motif in vivo. We provide evidence that methylation augments Scd6 repression activity. Arginine methylation defective (AMD) mutant of Scd6 rescues the growth defect caused by overexpression of Scd6, a feature of translation repressors in general. Live-cell imaging of the AMD mutant revealed that it is defective in inducing formation of stress granules. Live-cell imaging and pull-down results indicate that it fails to bind eIF4G1 efficiently. Consistent with these results, a strain lacking Hmt1 is also defective in Scd6-eIF4G1 interaction. Our results establish that arginine methylation augments Scd6 repression activity by promoting eIF4G1-binding. We propose that arginine methylation of translation repressors with RGG-motif could be a general modulator of their repression activity.

Item Type:	Journal Article
Publication:	NUCLEIC ACIDS RESEARCH
Additional Information:	Copy right for this article belongs to the OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	30 Dec 2016 06:00
Last Modified:	30 Dec 2016 06:00
URI:	http://eprints.iisc.ac.in/id/eprint/55604

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