Transcription regulator of erythrocyte development. Binds to the CACCC box in the beta-globin gene promoter and activates transcription. Probably serves as a general switch factor for erythroid development. When sumoylated, acts as a transcriptional repressor by promoting interaction with CDH2/MI2beta and also represses megakaryocytic differentiation. Interacts with CBP and EP300; the interactions enhance the transactivation activity. Interacts with PCAF; the interaction does not acetylate EKLF and inhibits its transactivation activity (By similarity). Interacts with CDH4; the interaction is SUMO-dependent and leads to transcriptional repression. Colocalizes with SUMO1 in nuclear speckles. Erythroid-specific. Only expressed in bone marrow and spleen. The 9aaTAD motif is a transactivation domain present in a large number of yeast and animal transcription factors. Acetylated; can be acetylated on both Lys-270 and Lys-288. Acetylation on Lys-270 (by CBP) appears to be the major site affecting EKLF transactivation activity. Sumoylated; sumoylation, promoted by PIAS1, leads to repression of megakaryocyte differentiation. Also promotes the interaction with the CDH4 subunit of the NuRD repression complex. Phosphorylated primarily on serine residues in the transactivation domain. Phosphorylation on Thr-23 is critical for the transactivation activity. Belongs to the krueppel C2H2-type zinc-finger protein family.