The 26S proteasome plays a central role in the degradation of regulatory proteins involved in a variety of developmental processes. It consists of two multisubunit protein complexes: the proteolytic core protease and the regulatory particle (RP).The RPN1 subunit belongs to the base complex of the RP and is known to physically interact with two proteins carrying ubiquitin-like domains, Rad23 and Dsk2.
Actin is an ancient conserved protein that is encoded by multiple isovariants in multi-cellular organisms. There are eight functional actin genes in the Arabidopsis genome.