Abstract
Ubiquitin(Ub)/26S proteasome pathway plays an essential housekeeping role to eliminate the proteins which are damaged or misfolded. It is also essential for most, if not all, aspects of cellular regulation by removing rate-limiting enzymes and desmantling existing regulatory networks as a way to fine-tune homeostasis, adapt to new environments, and redirect growth and development. The 26S proteasome consists of two multisubunit complexes, 20S core particle (CP) and 19S regulatory particle (RP). The RP presumably functions to identify appropriate substrates which are degraded, to release the attached Ubs, to open the CP gate, and to unfold the substrate proteins leading into the CP. The RP contains three non-ATPase subunits (RPN) and a ring of six AAA-ATPase subunits (RPT).
We examined the isolation and characterization of the mutants which are defective in RPT subunit in Arabidopsis. The function of RPTs will be discussed in terms of cell size regulation.
