Description
Ribosomal protein S6 kinases (RSK) are a family of broadly expressed serine/threonine kinases activated in response to mitogenic stimuli, including tumor-promoting growth factors and phorbol esters. RSKs are positioned downstream of the Raf-MEK-ERK signal transduction pathway, and are directly phosphorylated by ERK1 and ERK2extracellular kinases. Active RSKs appear to play a significant role in transcriptional regulation, translocation to the nucleus, and phosphorylation of c-Fos and CREBs.
Current models suggest that RSK activation requires a binding of active ERK1/2 to a docking site at the carboxyl end of RSK. ERK moored to RSK1 phosphorylate at several sites, including the CTD activation loop (carboxyl-terminal kinase domain). The CTD autophosphorylates Serine 380, a site in the central hydrophobic region.
The AlphaLISA™ SureFire® Ultra™ p-RSK1 (Ser380) assay is a sandwich immunoassay for the quantitative detection of phospho-RSK1 (phosphorylated on Ser380) in cellular lysates, using Alpha Technology.
Formats:
The HV (high volume) kit contains reagents to run 100 wells in 96-well format, using a 60 μL reaction volume.
The 500-point kit contains enough reagents to run 500 wells in 384-well format, using a 20 μL reaction volume.
The 10,000-point kit contains enough reagents to run 10,000 wells in 384-well format, using a 20 μL reaction volume.
The 50,000-point kit contains enough reagents to run 50,000 wells in 384-well format, using a 20 μL reaction volume.
AlphaLISA SureFire Ultra kits are compatible with:
Cell and tissue lysates
Antibody modulators
Biotherapeutic antibodies
Alpha SureFire kits can be used for:
Cellular kinase assays
Receptor activation studies
Screening
Phospho-AlphaLISA SureFire Ultra assay principle
The Phospho-AlphaLISA SureFire Ultra assay measures a target protein when phosphorylated at a specific residue in a biological sample (e.g. cell lysate).
The assay uses two antibodies which recognize the phospho epitope and a distal epitope on the target protein. AlphaLISA assays require two bead types: Acceptor and Donor Beads. Acceptor Beads are coated with a proprietary CaptSure™ agent to specifically immobilize the assay specific antibody, labeled with a CaptSure tag. Donor Beads are coated with streptavidin to capture one of the detection antibodies, which is biotinylated. In the presence of phosphorylated protein, the two antibodies bring the Donor and Acceptor Beads in close proximity whereby the singlet oxygen transfers energy to excite the Acceptor Bead, allowing for the generation of a luminescent Alpha signal. The amount of light emission is directly proportional to the quantity of phosphoprotein present in the sample.
Phospho-AlphaLISA SureFire Ultra two-plate assay protocol
The two-plate protocol involves culturing and treating the cells in a 96-well plate before lysis, then transferring lysates into a 384-well OptiPlate™ plate before the addition of Phospho-AlphaLISA SureFire Ultra detection reagents. This protocol enables cell viability and confluence to be monitored. In addition, lysates from a single well can be used to measure multiple targets.
Phospho-AlphaLISA SureFire Ultra one-plate assay protocol
Detection of Phosphorylated target protein with AlphaLISA SureFire Ultra reagents can be performed in a single plate used for culturing, treatment, and lysis. No washing steps are required. This HTS designed protocol allows for miniaturization while maintaining robust AlphaLISA SureFire Ultra quality.
