P300/CBP‐associated factor regulates transcription and function of isocitrate dehydrogenase 2 during muscle differentiation

Abstract

The epigenetic enzyme p300/CBP‐associated factor (PCAF) belongs to the GCN5‐related N‐acetyltransferase (GNAT) family together with GCN5. Although its transcriptional and post‐translational function is well characterized, little is known about its properties as regulator of cell metabolism. Here, we report the mitochondrial localization of PCAF conferred by an 85 aa mitochondrial targeting sequence (MTS) at the N‐terminal region of the protein. In mitochondria, one of the PCAF targets is the isocitrate dehydrogenase 2 (IDH2) acetylated at lysine 180. This PCAF‐regulated post‐translational modification might reduce IDH2 affinity for isocitrate as a result of a conformational shift involving predictively the tyrosine at position 179. Site‐directed mutagenesis and functional studies indicate that PCAF regulates IDH2, acting at dual level during myoblast differentiation: at a transcriptional level together with MyoD, and at a post‐translational level by direct modification of lysine acetylation in mitochondria. The latter event determines a decrease in IDH2 function with negative consequences on muscle fiber formation in C2C12 cells. Indeed, a MTS‐deprived PCAF does not localize into mitochondria, remains enriched into the nucleus, and contributes to a significant increase of muscle‐specific gene expression enhancing muscle differentiation. The role of PCAF in mitochondria is a novel finding shedding light on metabolic processes relevant to early muscle precursor differentiation.—Savoia, M., Cencioni, C., Mori, M., Atlante, S., Zaccagnini, G., Devanna, P., Di Marcotullio, L., Botta, B., Martelli, F., Zeiher, A. M., Pontecorvi, A., Farsetti, A., Spallotta, F., Gaetano, C. P300/CBP‐associated factor regulates transcription and function of isocitrate dehydrogenase 2 during muscle differentiation. FASEB J. 33, 4107–4123 (2019). http://www.fasebj.org

Mitochondrial DNA: Epigenetics and environment

“…These modifications include lysine methylation, phosphorylation, acetylation, ubiquitylation, sumoylation, and PARylation (reviewed in Bannister and Kouzarides, 2011). The enzymatic acetylation inside mitochondria has been recently acknowledged as four acetyl transferases ACAT1, MOF, GCN5L1, and PCAF have been identified in the mitochondria and are responsible for regulation of acetylation levels of mitochondrial proteins (Fan et al, 2014;Chatterjee et al, 2016;Wang et al, 2017;Savoia et al, 2019). It is estimated that approximately 63% of proteins that are localized within the mitochondrion contain lysine acetylation sites, and in one study conducted in 2011, 216 phosphopeptides were identified from mitochondrial preparations (Zhao et al, 2011).…”

Protein acetylation and deacetylation: An important regulatory modification in gene transcription (Review)

“…As mitochondria carry out a number of essential functions in metabolism, the study of Mechanisms and Dynamics of Protein Acetylation in Mitochondria becomes necessary. PCAF functions as a lysine acetyltransferase inside mitochondria (143). PCAF affects intermediary metabolism by acetylating isocitrate dehydrogenase 2 (IDH2) at K180 in the mitochondrial matrix, which interferes with the catalytic mechanisms of isocitrate binding and oxidation (143).…”

“…PCAF functions as a lysine acetyltransferase inside mitochondria (143). PCAF affects intermediary metabolism by acetylating isocitrate dehydrogenase 2 (IDH2) at K180 in the mitochondrial matrix, which interferes with the catalytic mechanisms of isocitrate binding and oxidation (143). A number of central enzymes in mitochondria are deacetylated by SIRT3, which reverses the suppressive effect of acetylation, leading to enhanced oxidative metabolism (144).…”

“…PCAF acetylates isocitrate dehydrogenase 2 (IDH2) at lysine 180, which may reduce IDH2 affinity for isocitrate. In this way, PACF influences myoblast differentiation (143). CCAAT/enhancer-binding protein a (C/EBPα), which can be acetylated by p300, regulates the transcription of metabolic genes and further enhances its transactivation activity (147).…”

Downregulation of P300/CBP-Associated Factor Attenuates Myocardial Ischemia-Reperfusion Injury Via Inhibiting Autophagy

“…How to effectively reduce MIRI remains a major challenging research focus. P300/CBP-associated factor (PCAF), a transcriptional co-activator with intrinsic histone acetyltransferase activity, participates in transcriptional regulation of genes by acetylating histone and non-histone, and is involved in cell differentiation, apoptosis, tumor occurrence and so on [6][7][8]. In addition, studies have shown that PCAF is involved in the transcription of autophagy-related signaling pathway proteins and regulate autophagy [9].…”