Methylarginines within the RGG-Motif Region of hnRNP A1 Affect Its IRES Trans-Acting Factor Activity and Are Required for hnRNP A1 Stress Granule Localization and Formation
The functional role of asymmetric dimethylation within the hnRNP A1 RGG-motif region is unknown. Lysine substitution within the RGG-motif region increases hnRNP A1 ITAF activity by 40%. Asymmetric dimethylation of hnRNP A1 may serve to inhibit ITAF activity. Alanine substitution within the RGG-motif region abolishes hnRNP A1 ITAF activity and mRNA-binding ability. The hnRNP A1 alanine mutant inhibits stress granule formation in a dominant-negative manner.