MSK1 Protein, Human (Active, sf9, GST)

MSK1, a serine/threonine-protein kinase, plays a pivotal role in diverse cellular processes by orchestrating the mitogen or stress-induced phosphorylation of crucial transcription factors. In response to various stimuli such as UV-C irradiation, epidermal growth factor (EGF), and anisomycin, MSK1 phosphorylates transcription factors CREB1 and ATF1, contributing to gene activation by histone phosphorylation. It exerts control over RELA transcriptional activity, associating with glucocorticoid receptor NR3C1 in the cytoplasm to inhibit RELA and repress inflammatory gene expression upon glucocorticoid and TNF stimulation. In skeletal myoblasts, MSK1 is essential for the oxidative stress-induced phosphorylation of RELA at 'Ser-276.' Additionally, MSK1 participates in erythropoietin-stimulated cells, regulating the 'Ser-727' phosphorylation of STAT3 and its transcriptional potential. By phosphorylating ETV1/ER81, particularly at 'Ser-191' and 'Ser-216,' MSK1 modulates its ability to stimulate transcription, potentially influencing developmental processes and breast tumor formation. Notably, MSK1 directly represses transcription by phosphorylating 'Ser-1' of histone H2A and activates immediate early genes, including c-fos/FOS and c-jun/JUN, by phosphorylating 'Ser-10' and possibly 'Ser-28' of histone H3. In lipopolysaccharide-stimulated macrophages, MSK1 limits the production of pro-inflammatory cytokines, likely by inducing the transcription of MAP kinase phosphatase DUSP1 and anti-inflammatory cytokine interleukin 10 (IL10) through CREB1 and ATF1. Furthermore, MSK1 is implicated in neuronal cell death following excitotoxic injury and phosphorylates TRIM7 at 'Ser-107' in response to growth factor signaling via the MEK/ERK pathway, stimulating its ubiquitin ligase activity.