Ribosomal protein S6 kinase alpha-1 (RPS6KA1)

In fibroblast, is required for EGF-stimulated phosphorylation of CREB1, which leads to the following transcriptional activation of numerous immediate-early genes. Upon insulin- derived signal, acts indirectly on the transcription regulation of many genes by phosphorylating GSK3B at'Ser-9' and inhibiting its activity.

Phosphorylates RPS6 in response to serum or EGF via an mTOR-independent mechanism and promotes translation initiation by facilitating assembly of the pre-initiation complicated. In response to insulin, phosphorylates EIF4B, improving EIF4B affinity for the EIF3 complicated and stimulating cap-dependent translation.