The RUNX1:CBFB complex can bind to the promoter of the GP1BA (CD42b) gene, encoding Platelet glycoprotein Ib alpha chain. Based on the analogy with the ITGA2B gene transcription (Zhao et al. 2008), the PRMT1-mediated arginine-methylation increases transcriptional activity of the RUNX1:CBFB complex at the GP1BA promoter (Herglotz et al. 2013). In addition to the RUNX1:CBFB complex, the complex of GATA1 and ZFPM1 (FOG1) (Freson et al. 2003) is also recruited to the GP1BA promoter (Herglotz et al. 2013), likely through the interaction between GATA1 and RUNX1 (Elagib et al. 2003). The zinc finger domain of GATA1 is involved in binding to RUNX1 (Xu et al. 2006). Along with RUNX1 and GATA1, histone acetyltransferases p300 (EP300) and PCAF (KAT2B), as well as the WDR5-containing histone methyltransferase MLL complex are also recruited to the GP1BA promoter. Dimethylation of histone H3 on lysine residue K4 (K5 when taking into account the initiator methionine), known as the H3K4me2 mark, is characteristic of nucleosomes associated with megakaryocyte specific promoters, including the GP1BA gene, prior to the onset of differentiation (Herglotz et al. 2013).
Van Geet, C,