title: Proteasomes and protein conjugation across domains of life.
abstract: Like other energy-dependent proteases, proteasomes, which are found across the three domains of life, are self-compartmentalized and important in the early steps of proteolysis. Proteasomes degrade improperly synthesized, damaged or misfolded proteins and hydrolyse regulatory proteins that must be specifically removed or cleaved for cell signalling. In eukaryotes, proteins are typically targeted for proteasome-mediated destruction through polyubiquitylation, although ubiquitin-independent pathways also exist. Interestingly, actinobacteria and archaea also covalently attach small proteins (prokaryotic ubiquitin-like protein (Pup) and small archaeal modifier proteins (Samps), respectively) to certain proteins, and this may serve to target the modified proteins for degradation by proteasomes.
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700, USA. jmaupin@ufl.edu
authors.forename: Julie
authors.initials: J
authors.lastname: Maupin-Furlow
mesh_terms: D039903:Actinobacteria / Q000378:metabolism; D001105:Archaea / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology; D056890:Eukaryota / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism / Q000502:physiology*; D011487:Protein Conformation; D017510:Protein Folding; D011506:Proteins / Q000378:metabolism* / Q000502:physiology; D059748:Proteolysis; D015398:Signal Transduction; D054875:Ubiquitination; D014452:Ubiquitins / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D011506:Proteins; D014452:Ubiquitins; D046988:Proteasome Endopeptidase Complex