Phospho-RSK1 p90(Thr359/Ser363) Antibody (YA6095) (YA6095),MedChemexpress,HY-P86403

p90RSK is a serine/threonine-protein kinase that functions downstream of ERK (MAPK1/ERK2 and MAPK3/ERK1) signaling, mediating mitogenic and stress-induced activation of transcription factors CREB1, ETV1/ER81, and NR4A1/NUR77, while regulating translation through phosphorylation of RPS6 and EIF4B. It modulates cellular proliferation, survival, and differentiation by influencing mTOR signaling and suppressing the pro-apoptotic functions of BAD and DAPK1. In fibroblasts, p90RSK is essential for EGF-stimulated CREB1 phosphorylation, leading to transcriptional activation of immediate-early genes. Upon mitogenic stimulation (e.g., EGF or PMA), it phosphorylates and activates NR4A1/NUR77, ETV1/ER81, and the cofactor CREBBP. Under insulin signaling, p90RSK indirectly regulates gene transcription by phosphorylating GSK3B at Ser-9 to inhibit its activity. It also promotes translation initiation by phosphorylating RPS6 in an mTOR-independent manner and enhances EIF4B binding to the EIF3 complex for cap-dependent translation. Within the mTOR nutrient-sensing pathway, p90RSK phosphorylates TSC2 at Ser-1798 to inhibit its suppression of mTOR signaling and modifies RPTOR to regulate mTORC1 activity. Additionally, it provides feedback regulation of mTORC1/2 by phosphorylating DEPTOR. The kinase supports cell survival by phosphorylating pro-apoptotic proteins BAD and DAPK1 and promotes hepatic stellate cell survival via CEBPB phosphorylation in response to CCl4. It regulates the cell cycle by phosphorylating CDKN1B, preventing its nuclear translocation and G1 arrest. Under mTORC1 activation, p90RSK phosphorylates EIF4B at Ser-406/422 to stimulate SLC4A7 mRNA translation. By similar mechanisms, it facilitates late-stage transcription and translation of viral lytic genes during Kaposi’s sarcoma-associated herpesvirus/HHV-8 infection.

RPS6KA1; MAPKAPK1A; RSK1; Ribosomal protein S6 kinase alpha-1; S6K-alpha-1; 90 kDa ribosomal protein S6 kinase 1; p90-RSK 1; p90RSK1; p90S6K; MAP kinase-activated protein kinase 1a; MAPK-activated protein kinase 1a; MAPKAP kinase 1a; MAPKAP