MEF2A

The process of differentiation from mesodermal precursor cells to myoblasts has led to the discovery of a variety of tissue-specific factors that regulate muscle gene expression. The myogenic basic helix-loop-helix proteins, including myoD (MIM 159970), myogenin (MIM 159980), MYF5 (MIM 159990), and MRF4 (MIM 159991) are one class of identified factors. A second family of DNA binding regulatory proteins is the myocyte-specific enhancer factor-2 (MEF2) family. Each of these proteins binds to the MEF2 target DNA sequence present in the regulatory regions of many, if not all, muscle-specific genes. The MEF2 genes are members of the MADS gene family (named for the yeast mating type-specific transcription factor MCM1, the plant homeotic genes 'agamous' and 'deficiens' and the human serum response factor SRF (MIM 600589)), a family that also includes several homeotic genes and other transcription factors, all of which share a conserved DNA-binding domain.[supplied by OMIM

MEF2A

Transcriptional activator which binds specifically to the MEF2 element, 5'-YTA[AT]4TAR-3', found in numerous muscle-specific genes. Also involved in the activation of numerous growth factor- and stress-induced genes. Mediates cellular functions not only in skeletal and cardiac muscle development, but also in neuronal differentiation and survival. Plays diverse roles in the control of cell growth, survival and apoptosis via p38 MAPK signaling in muscle-specific and/or growth factor-related transcription. In cerebellar granule neurons, phosphorylated and sumoylated MEF2A represses transcription of NUR77 promoting synaptic differentiation. Associates with chromatin to the ZNF16 promoter.

Apoptotic process Source: UniProtKB-KW
Cardiac conduction Source: UniProtKB
Cell differentiation Source: GO_Central
Cellular response to calcium ion Source: UniProtKB
Dendrite morphogenesis Source: UniProtKB
ERK5 cascade Source: UniProtKB
Heart development Source: UniProtKB
MAPK cascade Source: UniProtKB
Mitochondrial genome maintenance Source: UniProtKB
Mitochondrion distribution Source: UniProtKB
Muscle organ development Source: UniProtKB
Negative regulation of transcription by RNA polymerase II Source: UniProtKB
Positive regulation of cardiac muscle hypertrophy Source: BHF-UCL
Positive regulation of gene expression Source: Ensembl
Positive regulation of glucose import Source: Ensembl
Positive regulation of transcription by RNA polymerase II Source: UniProtKB
Regulation of transcription by RNA polymerase II Source: GO_Central
Transcription, DNA-templated Source: UniProtKB
Ventricular cardiac myofibril assembly Source: UniProtKB

Nucleus

Coronary artery disease, autosomal dominant, 1 (ADCAD1):
A common heart disease characterized by reduced or absent blood flow in one or more of the arteries that encircle and supply the heart. Its most important complication is acute myocardial infarction.

Constitutive phosphorylation on Ser-408 promotes Lys-403 sumoylation thus preventing acetylation at this site. Dephosphorylation on Ser-408 by PPP3CA upon neuron depolarization promotes a switch from sumoylation to acetylation on residue Lys-403 leading to inhibition of dendrite claw differentiation. Phosphorylation on Thr-312 and Thr-319 are the main sites involved in p38 MAPK signaling and activate transcription. Phosphorylated on these sites by MAPK14/p38alpha and MAPK11/p38beta, but not by MAPK13/p38delta nor by MAPK12/p38gamma. Phosphorylation on Ser-408 by CDK5 induced by neurotoxicity inhibits MEF2A transcriptional activation leading to apoptosis of cortical neurons. Phosphorylation on Thr-312, Thr-319 and Ser-355 can be induced by EGF.
Sumoylation on Lys-403 is enhanced by PIAS1 and represses transcriptional activity. Phosphorylation on Ser-408 is required for sumoylation. Has no effect on nuclear location nor on DNA binding. Sumoylated with SUMO1 and, to a lesser extent with SUMO2 and SUMO3. PIASx facilitates sumoylation in postsynaptic dendrites in the cerebellar cortex and promotes their morphogenesis (By similarity).
Acetylation on Lys-403 activates transcriptional activity. Acetylated by p300 on several sites in diffentiating myocytes. Acetylation on Lys-4 increases DNA binding and transactivation (By similarity). Hyperacetylation by p300 leads to enhanced cardiac myocyte growth and heart failure.
Proteolytically cleaved in cerebellar granule neurons on several sites by caspase 3 and caspase 7 following neurotoxicity. Preferentially cleaves the CDK5-mediated hyperphosphorylated form which leads to neuron apoptosis and transcriptional inactivation.