Phospho-Rb (Ser807/811) Cellular Kit, 50000 Tests

This HTRF cell-based assay conveniently and accurately quantifies phosphorylated Retinoblastoma protein at Ser807/811. Rb belongs to the pocket protein family, and acts as a tumor suppressor, regulating cell cycle progression. The active underphosphorylated Rb form interacts and represses the transcriptional activity of E2F factors, thereby preventing G0/G1 cell cycle transition and progression in the cell cycle. In the presence of mitogenic signals, cyclin D-CDK4/6, followed by cyclin E-CDK2, sequentially phosphorylate and inactivate Rb, releasing the E2F transcription factors required for cell cycle progression.