Abstract
Protein arginine methyltransferase 5 (PRMT5) is a member of the arginine methyltransferase protein family that critically mediates the symmetric dimethylation of Arg-3 at histone H4 (H4R3me2s) and is involved in many key cellular processes, including hematopoiesis. However, the post-translational modifications (PTMs) of PRMT5 that may affect its biological functions remain less well-understood. In this study, using MS analyses, we found that PRMT5 itself is methylated in human erythroleukemia Lys-562 cells. Biochemical assays revealed that coactivator-associated arginine methyltransferase 1 (CARM1) interacts directly with and methylates PRMT5 at Arg-505 both in vivo and in vitro. Substitutions at Arg-505 significantly reduced PRMT5's methyltransferase activity, decreased H4R3me2s enrichment at the γ-globin gene promoter, and increased the expression of the γ-globin gene in Lys-562 cells. Moreover, CARM1 knockdown consistently reduced PRMT5 activity and activated γ-globin gene expression. Importantly, we show that CARM1-mediated methylation of PRMT5 is essential for the intracellular homodimerization of PRMT5 to its active form. These results thus reveal a critical PTM of PRMT5 that represses human γ-globin gene expression. We conclude that CARM1-mediated asymmetric methylation of PRMT5 is critical for its dimerization and methyltransferase activity leading to the repression of γ-globin expression. Given PRMT5's crucial role in diverse cellular processes, these findings may inform strategies for manipulating its methyltransferase activity for managing hemoglobinopathy or cancer.
Highlights
Protein arginine methyltransferase 5 (PRMT5) is a member of the arginine methyltransferase protein family that critically mediates the symmetric dimethylation of Arg-3 at histone H4 (H4R3me2s) and is involved in many key cellular processes, including hematopoiesis
In this study, using MS analyses, we found that PRMT5 itself is methylated in human erythroleukemia Lys-562 cells
We found that PRMT5 could be methylated by coactivator-associated arginine methyltransferase 1 (CARM1) at the highly conserved residue arginine 505 (Arg-505)
Summary
Protein arginine methyltransferase 5 (PRMT5) is a member of the arginine methyltransferase protein family that critically mediates the symmetric dimethylation of Arg-3 at histone H4 (H4R3me2s) and is involved in many key cellular processes, including hematopoiesis. We show that CARM1-mediated methylation of PRMT5 is essential for the intracellular homodimerization of PRMT5 to its active form These results reveal a critical PTM of PRMT5 that represses human ␥-globin gene expression. CARM1 can methylate nonhistone substrates acting as gene coregulators, such as the transcription factors p/CIP, pRB, SOX2, and the NF-B subunit p65 (14 –17); the transcriptional coactivators CBP/p300 and SRC3 [18, 19]; the chromatin remodeling factor BAF155 [20], PAX7 [21]; the CARM1 repressed human ␥-globin gene expression indirectly through the methylation of PRMT5, which increased histone H4R3me2s enrichment at the ␥-promoter in Lys-562 cells. Our study reveals a novel post-translational modification of PRMT5 by CARM1 that modulates human ␥-globin gene expression
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.