The activity of retinoblastoma protein (Rb) is regulatedprimarily by phosphorylation at various serine/threonine residues.Specific patterns of pRb phosphorylation generate pRbconformational variants that mediate distinct protein-proteininteractions. In an experimental cell system with a mutation in theRb gene that encodes alanine rather than serine, which isphosphorylated in the wild-type Rb, you observe that the cell isunable to enter into the cell cycle. What this observation suggestand how do you design an experiment to substantiate yoursuggestion?
