Author + information
- Yusuke Miyazaki1,2,
- Yasufumi Katanasaka1,2,3,
- Yoichi Sunagawa1,2,3,
- Hiromichi Wada2,
- Koji Hasegawa2 and
- Tatsuya Morimoto1,3
Heart failure is one of the leading causes of death in industrialized countries, and cardiac hypertrophy is a risk factor for heart failure. We have previously shown that p300/GATA4 pathway is essential for cardiac hypertrophy. To investigate the precise regulatory mechanism, we performed LC/LC-MS analysis and identified protein arginine methyltransferase 5 (PRMT5) as a novel GATA4 binding protein. PRMT5 is known to symmetrically methylate histone H4 arginine 3 and various proteins such as transcriptional factor. However, its role on cardiac hypertrophy and p300/GATA4 pathway is still not unclear.
We generated heart-specific PRMT5 transgenic (PRMT5-TG) mice and examined the role in cardiac hypertrophy induced by transverse aortic constriction (TAC). Primary cultured neonatal rat cardiomyocytes were treated with EPZ015666, a specific PRMT5 inhibitor, and stimulated with phenylephrine (PE) for 48 hours. The surface area of the cardiomyocytes and promoter activities of hypertrophy-response genes were measured. We finally performed GST pull-down assay and methyltransferase assay to examine the binding of PRMT5 to GATA4 or p300 and arginine methylation.
Cardiac overexpression of PRMT5 promoted pressure overload-induced cardiac hypertrophy and significantly decreased cardiac function. PRMT5 directly bound to both GATA4 and p300 in vitro. However, PRMT5 methylated only p300 but not GATA4. To identify the methylation site of p300, we performed methylation assay with p300 fragments and found that PRMT5 methylated p300 on arginine 200. Methylation of p300 by PRMT5 was inhibited by EPZ015666 in vitro. In neonatal rat cardiomyocyte, EPZ015666 also repressed PE-induced cardiomyocyte hypertrophy and hypertrophic gene transcriptions.
These results indicated that PRMT5 induce cardiac hypertrophy through methylation of p300. PRMT5 specific inhibitor might become a novel therapeutic compound on cardiac hypertrophy.