Distinct alternative splicing patterns of mediator subunit genes during endothelial progenitor cell differentiation.

Mediator (MED) is a fundamental component of the RNA polymerase II-mediated transcription machinery playing a pivotal role in the regulation of eukaryotic mRNA synthesis. Human MED complexes contain at least 30 distinct MED subunits. Our previous study, aimed to analyse MED complex during the pattern of endothelial progenitor cells (EPCs) differentiation, found an alternative transcript of MED30 subunit expressed only in circulating immature progenitor cells. Here, we report two novel transcripts of MED12 and MED19 subunits both generated by alternative splicing and displaying similar expression patterns, thereby indicating their involvement during endothelial cell differentiation.