Members of the RSK (the p90 ribosomal S6 kinase) family of serine/threonine kinases are substrates of ERK (the Ras/extracellular signal-regulated kinase) (1). The RSK family consists of four isoforms (RSK1 to -4) and two structurally related cousins, called RSK-like protein kinase (RLPK/MSK1) and RSKB (MSK2). RSK2 is expressed in most tissues including heart, brain, placenta, liver, kidney and pancreas, with predominant expression in skeletal muscle (4-5). The small death effector domain protein PEA-15 inhibits RSK2 nuclear translocation, but the biological function of this interaction is unknown6. Activated RSK2 can also be found in the cytoplasm of stimulated cells suggesting that RSK2 substrates may exist in both nuclear and cytoplasmic compartments (7). A phosphate-binding pocket in the kinase domain of RSK2 is used for intramolecular interaction with its own phosphorylated hydrophobic motif, an interaction that induces a synergistic stimulation of RSK2 catalytic activity, whereas mutation of the phosphate-binding pocket leads to a reduction in the overall kinase activity of RSK28. Defects in the RSK2 gene are the cause of Coffin-Lowry syndrome, an X-linked dominant disorder characterized by psychomotor and growth retardation and facial, hand and skeletal malformations9-10. Numerous mutations have been identified in the RSK2 gene that result in truncated or inactive RSK2 proteins (11-12).

Suitable for use in Western Blot. Other applications not tested.

Western Blot: 1-3ug/ml. Identifies a single band at ~84 kD Optimal dilutions to be determined by the researcher.

Store product at 4°C in the dark. DO NOT FREEZE! Stable at 4°C for 12 months after receipt as an undiluted liquid. Dilute required amount only prior to immediate use. Further dilutions can be made in assay buffer. Caution: MaxLight™650 conjugates are sensitive to light. For maximum recovery of product, centrifuge the original vial prior to removing the cap.

Note: Applications are based on unconjugated antibody.

Synthetic peptide corresponding to the N-terminal region of the human and mouse RSK2 (ribosomal S6 kinase 2, ribosomal protein S6 kinase alpha 3, 90kD ribosomal protein S6 kinase 3, and MAP kinase-activated protein kinase 1b).

Supplied as a liquid in PBS, pH 7.2. No preservatives added. Labeled with MaxLight™650.

Purified by immunoaffinity chromatography.

Recognizes human RSK2 at ~84kD. Species Crossreactivity: mouse. Does not react with overexpressed RSK1, RSK3 or RSK4. Reactivity has been confirmed with endogenously human placenta homogenates, HEK293 cell lysates, and fetal and adult mouse skeletal muscle homogenates, and exogenously with RSK-2-transfected HEK293 cells.