Posttranslational Modification of the 20S Proteasomal Proteins of the Archaeon Haloferax volcanii
Year: 2006
Type: article
Abstract: 20S proteasomes are large, multicatalytic proteases that play an important role in intracellular protein degradation. The barrel-like architecture of 20S proteasomes, formed by the stacking of four heptameric protein rings, is highly conserved from archaea to eukaryotes. The outer two rings are composed of alpha-type subunits, and the inner two rings are composed of beta-type subunits. The halophilic archaeon Haloferax volcanii synthesizes two different alpha-type proteins, alpha1 and alpha2, and one beta-type protein that assemble into at least two 20S proteasome subtypes. In this study, we demonstrate that all three of these 20S proteasomal proteins (alpha1, alpha2, and beta) are modified either post- or cotranslationally. Using electrospray ionization quadrupole time-of-flight mass spectrometry, a phosphorylation site of the beta subunit was identified at Ser129 of the deduced protein sequence. In addition, alpha1 and alpha2 contained N-terminal acetyl groups. These findings represent the first evidence of acetylation and phosphorylation of archaeal proteasomes and are one of the limited examples of post- and/or cotranslational modification of proteins in this unusual group of organisms.
Source: Journal of Bacteriology
DOI: 10.1128/jb.00943-06
Institution: University of Florida
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: G222768804, IDENTIFICATION OF PROTEASOME SUBSTRATES OF HALOFERAX VOLCANII - A DEGRADOMIC APPROACH, Dual function ubiquitin-like proteins in post-translational regulation and sulfur mobilization, G5727668983, PROTEASOMES AND POST-TRANSLATIONAL MODIFICATION OF HALOFERAX VOLCANII PROTEINS, G7191526401
OpenAlex ID: W2115847027