Ribosomal protein S6 kinase alpha-4 (RPS6KA4)

Serine/threonine-protein kinase that's required for the mitogen or stress-induced phosphorylation of the transcription factors CREB1 and ATF1 and for the regulation of the transcription factor RELA, which contributes to gene activation by histone phosphorylation and works in the regulation of inflammatory genes. Phosphorylates CREB1 and ATF1 in response to mitogenic or stress stimuli like UV-C irradiation, epidermal growth factor (EGF) and anisomycin.

Plays an important role in the control of RELA transcriptional activity in response to TNF. Phosphorylates'Ser-10' of histone H3 in reaction to mitogenics, stress stimulation and EGF, which results in the transcriptional activation of several immediate early genes, including proto-oncogenes c-fos/FOS and c-jun/JUN.