Phospho-MSK1(Ser360) Antibody (YA6243)

MSK1 (mitogen- and stress-activated protein kinase 1) is a predominantly nuclear serine/threonine kinase that functions downstream of the ERK1/2 and p38 MAPK pathways, integrating mitogenic and stress signals into transcriptional responses through phosphorylation-dependent activation mechanisms^[1][2]. MSK1 regulates gene expression by phosphorylating key nuclear substrates, including CREB, ATF1, and histone H3, thereby controlling immediate-early gene induction and chromatin-associated transcriptional programs^[2][3]. Mechanistically, activation of upstream MAPKs promotes sequential phosphorylation and autophosphorylation events within MSK1, enabling its N-terminal kinase domain to phosphorylate downstream targets involved in stimulus-responsive gene regulation^[1][2]. In disease-relevant systems, MSK1 contributes to anti-inflammatory transcriptional networks, regulates cytokine expression, and participates in neuronal proliferation, synaptic plasticity, and neurogenesis-related processes^[2]. MSK1 also functions as a chromatin-associated transcriptional coactivator, directly interacting with p53 and promoting p21 gene expression through p53-dependent histone H3 phosphorylation at target promoters^[3]. Compared with the closely related isoform MSK2, MSK1 shares substantial functional overlap and is often considered functionally redundant in many MAPK-dependent signaling contexts, although isoform-specific expression patterns and experimental models continue to support investigation of distinct biological contributions^[2]. For experimental applications, pharmacological inhibitors such as H89 and dimethylfumarate have been used to suppress MSK1/MSK2 signaling and evaluate downstream transcriptional and inflammatory responses in cellular and disease models^[2].