Phospho- and total Phospholamban assays for monitoring CaMKII activation
Cisbio's cell-based homogeneous HTRF® phospho-Phospholamban (Thr17) immunoassay enables the quantitative detection of Phospholamban (PLN) phosphorylated on Threonine 17. The HTRF® total PLN assay kit is designed for the quantitative detection of total PLN, phosphorylated and unphosphorylated, to normalize the phosphorylation status of PLN with respect to its steady-state level in cells. The buffers of the HTRF® phospho- and total PLN assays are compatible, enabling an analysis of the phosphorylated and the total protein populations from one lysate sample. The increase in intracellular Ca2+ causes the activation of CaMKII. CaMKII in turn phosphorylates PLN at the Thr17 residue. Dephosphorylated PLN inhibits SERCA2a, whereas phosphorylation of PLN at either the Ser16 site by PKA or the Thr17 site by CaMKII reverses this SERCA2a inhibition. The PLN phosphorylation state regulates the activity of this Ca2+ pump. Amenable to low-volume formats, use of the HTRF® phospho- PLN (Thr17) assay ranges from basic research to high throughput drug screening.