Patent ID: 7074620

Claim:
A method of reducing the level and/or activity of a target protein in an eukaryotic cell via the activation of ubiquitination of said target protein comprising contacting said cell with a compound comprising; a) a ubiquitination recognition element which is able to bind to either the E3 or E2 elements of a ubiquitination system, wherein said ubiquitination recognition element has a molecular weight less than 30,000 and has a binding affinity for said E3 and/or E2 elements of the ubiquitination system of at least 10 4 M âˆ’1 and; b) a target protein binding element that is able to bind specifically to said target protein wherein said target protein binding element has a molecular weight of less than 30,000 and has a binding affinity for said target protein greater than 10 5 M âˆ’1 , wherein said ubiquitination recognition element is covalently linked to said target protein binding element, and wherein the level and/or activity of the target protein in the eukaryotic cell is reduced.