UCSD Nature Molecule Pages
Published online: 17 May 2005 | doi:10.1038/mp.a003584.01
Basis Sequence: Mouse
H. Garrett R Thompson1, James P Brody1
1Department of Biomedical Engineering, University of California, Irvine, CA 92697, US.
Correspondence should be addressed to James P Brody: email@example.com
Rpn8, also known as S12, has a relative molecular mass of 36,600 (Mr 36.6K) and is 96% identical to the mouse protein encoded by Mov-34. Mov-34 is a mutation occasionally found in the mouse, caused by retroviral integration, that is embryonic lethal. Rpn8 is well conserved among all known eukaryotes. Rpn8 is a non-ATPase component of the lid subassembly of the 19S regulatory complex (also known as PA700 or the regulatory particle). Two 19S regulatory complexes bind to each end of the 20S proteasome to form the 26S proteasome. The proteins that assemble to form the proteasome are similar. Rpn8 is most closely related to the protein encoded by Rpn11, which has deubiquitinating activity. Rpn8 lacks this enzymatic activity. The exact function of Rpn8 is unknown, but several domains and motifs for Rpn8 have been identified. These include the C-terminal KEKE motif, a putative site of protein-protein interaction; the Jun activation-domain binding protein (JAB) domain, originally described as a regulator of transcription; the MPR1p and PAD1p N-terminal (MPN) domain, which, along with surrounding sequences, has been shown to be important for pairing with S13 (Rpn11/POH1); and there is possibly even weak homology to a MAPKK activation loop motif. In summary, the exact function of Rpn8 is unknown; however, it is essential to development. It is probably involved with protein degradation and possibly with transcription.
Alternative names for this molecule:
Moloney leukemia virus 34; Mov-34; Mov34; Proteasome (prosome, macropain) 26S subunit, non-ATPase, 7; Psmd7; Rpn8; S12