English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The hyperthermophilic archaeonPyrococcus furiosus genome encodes three proteasome component proteins: one α protein (PF1571) and two β proteins (β1-PF1404 and β2-PF0159), as well as an ATPase (PF0115), referred to as proteasome-activating nucleotidase. Transcriptional analysis of theP. furiosus dynamic heat shock response (shift from 90 to 105°C) showed that the β1 gene was up-regulated over twofold within 5 minutes, suggesting a specific role during thermal stress. Consistent with transcriptional data, two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that incorporation of the β1 protein relative to β2 into the 20S proteasome (core particle [CP]) increased with increasing temperature for both native and recombinant versions. For the recombinant enzyme, the β2/β1 ratio varied linearly with temperature from 3.8, when assembled at 80°C, to 0.9 at 105°C. The recombinant α+β1+β2 CP assembled at 105°C was more thermostable than either the α+β1+β2 version assembled at 90°C or the α+β2 version assembled at either 90°C or 105°C, based on melting temperature and the biocatalytic inactivation rate at 115°C. The recombinant CP assembled at 105°C was also found to have different catalytic rates and specificity for peptide hydrolysis, compared to the 90°C assembly (measured at 95°C). Combination of the α and β1 proteins neither yielded a large proteasome complex nor demonstrated any significant activity. These results indicate that the β1 subunit in theP. furiosus 20S proteasome plays a thermostabilizing role and influences biocatalytic properties, suggesting that β subunit composition is a factor in archaeal proteasome function during thermal stress, when polypeptide turnover is essential to cell survival.

Role of the β1 Subunit in the Function and Stability of the 20S Proteasome in the Hyperthermophilic Archaeon Pyrococcus furiosus