Key Spec Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|H, M, R||IP, WB||Rb||Purified||Polyclonal Antibody|
|Description||Anti-Rsk2/MAPKAP Kinase 1b Antibody|
|Presentation||0.1M Tris-glycine, pH 7.4, 0.15M NaCl, 0.05% sodium azide before the addition of glycerol to 30%|
|Application||Detect Rsk2/MAPKAP Kinase 1b using this Anti-Rsk2/MAPKAP Kinase 1b Antibody validated for use in IP & WB.|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||2 years at -20°C|
|Material Size||100 µg|
|Anti-Rsk2/MAPKAP Kinase 1b (rabbit polyclonal IgG) -2504290||2504290|
|Anti-Rsk2/MAPKAP Kinase 1b - 18111||18111|
|Anti-Rsk2/MAPKAP Kinase 1b - 21911||21911|
|Anti-Rsk2/MAPKAP Kinase 1b - DAM151402||DAM151402|
|Anti-Rsk2/MAPKAP Kinase 1b -2556295||2556295|
|Reference overview||Application||Pub Med ID|
|Phosphorylation of histone H2B serine 32 is linked to cell transformation.|
Lau, AT; Lee, SY; Xu, YM; Zheng, D; Cho, YY; Zhu, F; Kim, HG; Li, SQ; Zhang, Z; Bode, AM; Dong, Z
The Journal of biological chemistry 286 26628-37 2011
Various types of post-translational modifications of the histone tails have been revealed, but a few modifications have been found within the histone core sequences. Histone core post-translational modifications have the potential to modulate nucleosome structure and DNA accessibility. Here, we studied the histone H2B core domain and found that phosphorylation of H2B serine 32 occurs in normal cycling and mitogen-stimulated cells. Notably, this phosphorylation is elevated in skin cancer cell lines and tissues compared with normal counterparts. The JB6 Cl41 mouse skin epidermal cell line is a well established model for tumor promoter-induced cell transformation and was used to study the function of H2B during EGF-induced carcinogenesis. Remarkably, cells overexpressing a nonphosphorylatable H2BS32A mutant exhibited suppressed growth and EGF-induced cell transformation, possibly because of decreased activation of activator protein-1, compared with control cells overexpressing wild type H2B. We identified ribosomal S6 kinase 2 (RSK2) as the kinase responsible for H2BS32 phosphorylation. Serum-starved JB6 cells contain very little endogenous H2BS32 phosphorylation, and EGF treatment induced this phosphorylation. The phosphorylation was attenuated in RSK2 knock-out MEFs and RSK2 knockdown JB6 cells. Taken together, our results demonstrate a novel role for H2B phosphorylation in cell transformation and show that H2BS32 phosphorylation is critical for controlling activator protein-1 activity, which is a major driver in cell transformation.
|Ataxia Telangiectasia Mutated Proteins, MAPKs, and RSK2 Are Involved in the Phosphorylation of STAT3|
Zhang, Y., et al
J Biol Chem, 278:12650-9 (2003) 2003
|RSK2 activity is regulated by its interaction with PEA-15.|
Vaidyanathan, Hema and Ramos, Joe W
J. Biol. Chem., 278: 32367-72 (2003) 2003
The ERK MAP (mitogen-activated protein) kinase cascade modulates many cellular processes including transcription, adhesion, growth, survival, and proliferation. One target substrate of ERK involved in regulating transcription is the p90 ribosomal S6 kinase (RSK) isozyme, RSK2. Here we demonstrate that a small death effector domain-containing protein called PEA-15 binds RSK2. RSK2 and PEA-15 (phosphoprotein enriched in astrocytes, 15 kDa) co-precipitated from cells and were colocalized in the cytoplasm. Furthermore, purified PEA-15 bound in vitro translated RSK2, suggesting that these proteins interact directly. PEA-15 does not bind to RSK1 and therefore exhibits some binding specificity. RSK2 binds the COOH terminus of PEA-15 and does not interact with its NH2-terminal death effector domain. We show that this interaction has functional consequences including the inhibition of RSK2-dependent CREB transcription. PEA-15 expression also blocks histone H3 phosphorylation, an RSK2-dependent event that may contribute to effects on gene expression. These results can be attributed to two effects of PEA-15 on RSK2. First, PEA-15 blocks nuclear accumulation of RSK2 after epidermal growth factor stimulation. Second, PEA-15 inhibits RSK2 kinase activity by 50%. A mutant of PEA-15 that binds RSK2 but is localized to the nucleus had no effect on RSK2-dependent transcription. Interestingly, this mutant also did not affect RSK2 kinase activity. This may indicate that cytoplasmic retention of RSK2 is also required for PEA-15 to impair kinase activity. PEA-15 does not alter ERK phosphorylation of RSK2 and is not itself a substrate of RSK2. Hence the effects of PEA-15 on RSK2 represent a novel mechanism for the regulation of RSK2-mediated signaling.
|Rapid immunoblot and kinase assay tests for a syndromal form of X linked mental retardation: Coffin-Lowry syndrome.|
Merienne, K, et al.
J. Med. Genet., 35: 890-4 (1998) 1998
Coffin-Lowry syndrome (CLS) is a syndromal form of X linked mental retardation, in which some associated facial, hand, and skeletal abnormalities are diagnostic features. Accurate diagnosis, critical for genetic counselling, is often difficult, especially in early childhood. We have recently shown that Coffin-Lowry syndrome is caused by mutations in the gene encoding RSK2, a growth factor regulated protein kinase. RSK2 mutations are very heterogeneous and most of them lead to premature termination of translation or to loss of phosphotransferase activity or both. In the present study, we have evaluated immunoblot and RSK2 kinase assays as a rapid and simple diagnostic test for CLS, using cultured lymphoblastoid or fibroblast cell lines. Western blot analysis failed to detect RSK2 in six patients, suggesting the presence of truncated proteins in these patients. This conclusion was confirmed in four patients, in whom the causative mutations, all leading to premature termination of translation, were identified. Of four patients showing a normal amount of RSK2 protein on western blot and tested for RSK2 phosphotransferase activity, one had a dramatically impaired activity. Analysis of the RSK2 cDNA sequence in this patient showed a mutation of a putative phosphorylation site that would be critical for RSK2 activity. Preliminary results show that, at least, the western blot protocol can be successfully applied to lymphocyte protein extracts prepared directly from blood samples. These assays promise to become important diagnostic tools for CLS, particularly with regard to very young patients with no family history of the condition.
|Coupling of the RAS-MAPK pathway to gene activation by RSK2, a growth factor-regulated CREB kinase.|
Xing, J, et al.
Science, 273: 959-63 (1996) 1996
A signaling pathway has been elucidated whereby growth factors activate the transcription factor cyclic adenosine monophosphate response element-binding protein (CREB), a critical regulator of immediate early gene transcription. Growth factor-stimulated CREB phosphorylation at serine-133 is mediated by the RAS-mitogen-activated protein kinase (MAPK) pathway. MAPK activates CREB kinase, which in turn phosphorylates and activates CREB. Purification, sequencing, and biochemical characterization of CREB kinase revealed that it is identical to a member of the pp90(RSK) family, RSK2. RSK2 was shown to mediate growth factor induction of CREB serine-133 phosphorylation both in vitro and in vivo. These findings identify a cellular function for RSK2 and define a mechanism whereby growth factor signals mediated by RAS and MAPK are transmitted to the nucleus to activate gene expression.
|Regulation and interaction of pp90(rsk) isoforms with mitogen-activated protein kinases|
Zhao, Y., et al
J Biol Chem, 271:29773-9 (1996) 1996