When fused to the N-terminal end of a protein of interest, Tag:degron(PND) can induce degradation of that protein in response to blue-light illumination. Tag:degron(PND) consists of an N-terminal ubiquitin moiety followed by an Arg residue and the LOV2 domain of the Avena sativa Phototropin 1 (PT1) gene. During translation, the ubiquitin moiety is removed co-translationally, resulting in a protein with an N-terminal Arg residue. This residue is a target for the N-end rule-mediated degradation pathway, but in the absence of blue-light illumination, the conformation of the LOV2 domain renders the Arg residue inaccessible. Upon illumination with blue light, conformational change of the LOV2 domain exposes the N-terminal Arg residue, inducing proteasome-mediated degradation of the Tag:degron(PND) sequence and the protein of interest to which it is fused (FBrf0249097).