question: Which is the E3 ubiquitin ligase which ubiquitinates IkB leading to its proteasomal degradation?
answer: IκB degradation involves ubiquitination mediated by a specific E3 ubiquitin ligase SCF(β-TrCP). SCF(β-TrCP) -mediated IκB ubiquitination and degradation is a very efficient process, often resulting in complete degradation of the key inhibitor IκBα within a few minutes of cell stimulation.