8 research outputs found
A Completely Reimplemented MPI Bioinformatics Toolkit with a New HHpred Server at its Core
COP9 Signalosome- and 26S Proteasome-dependent Regulation of SCFTIR1 Accumulation in Arabidopsis*S⃞
Ubiquitination and proteasome-mediated degradation of proteins are crucial
for eukaryotic physiology and development. The largest class of E3 ubiquitin
ligases is made up of the cullin-RING ligases (CRLs), which themselves are
positively regulated through conjugation of the ubiquitin-like peptide
RUB/NEDD8 to cullins. RUB modification is antagonized by the COP9 signalosome
(CSN), an evolutionarily conserved eight-subunit complex that is essential in
most eukaryotes and cleaves RUB from cullins. The CSN behaves genetically as
an activator of CRLs, although it abolishes CRL activity in vitro.
This apparent paradox was recently reconciled in different organisms, as the
CSN was shown to prevent autocatalytic degradation of several CRL substrate
adaptors. We tested for such a mechanism in the model plant
Arabidopsis by measuring the impact of a newly identified viable
csn2 mutant on the activity and stability of SCFTIR1, a
receptor to the phytohormone auxin and probably the best characterized plant
CRL. Our analysis reveals that not only the F-box protein TIR1 but also
relevant cullins are destabilized in csn2 and other Arabidopsis
csn mutants. These results provide an explanation for the auxin
resistance of csn mutants. We further observed in vivo a
post-translational modification of TIR1 dependent on the proteasome inhibitor
MG-132 and provide evidence for proteasome-mediated degradation of TIR1, CUL1,
and ASK1 (Arabidopsis SKP1 homolog). These results are consistent
with CSN-dependent protection of Arabidopsis CRLs from autocatalytic
degradation, as observed in other eukaryotes, and provide evidence for
antagonist roles of the CSN and 26S proteasome in modulating accumulation of
the plant CRL SCFTIR1
The eisosome core is composed of BAR domain proteins
The core components of eisosomes, Pil1 and Lsp1, are membrane-sculpting BAR proteins. In addition, TORC2 substrates Slm1 and Slm2 have F-BAR domains that are needed for targeting into eisosomes. Results support a model in which BAR domain protein-mediated membrane bending leads to domain formation within the plasma membrane
Going to extremes - a metagenomic journey into the dark matter of life
Aevarsson A, Kaczorowska A-K, Adalsteinsson BT, et al. Going to extremes - a metagenomic journey into the dark matter of life. FEMS microbiology letters. 2021: fnab067.The Virus-X-Viral Metagenomics for Innovation Value-project was a scientific expedition to explore and exploit uncharted territory of genetic diversity in extreme natural environments such as geothermal hot springs and deep-sea ocean ecosystems. Specifically, the project was set to analyse and exploit viral metagenomes with the ultimate goal of developing new gene products with high innovation value for applications in biotechnology, pharmaceutical, medical, and the life science sectors. Viral gene pool analysis is also essential to obtain fundamental insight into ecosystem dynamics and to investigate how viruses influence the evolution of microbes and multicellular organisms. The Virus-X Consortium, established in 2016, included experts from eight European countries. The unique approach based on high throughput bioinformatics technologies combined with structural and functional studies resulted in the development of a biodiscovery pipeline of significant capacity and scale. The activities within the Virus-X consortium cover the entire range from bioprospecting and methods development in bioinformatics to protein production and characterisation, with the final goal of translating our results into new products for the bioeconomy. The significant impact the consortium made in all of these areas was possible due to the successful cooperation between expert teams that worked together to solve a complex scientific problem using state-of-the-art technologies as well as developing novel tools to explore the virosphere, widely considered as the last great frontier of life. © The Author(s) 2021. Published by Oxford University Press on behalf of FEMS
Going to extremes - a metagenomic journey into the dark matter of life
Aevarsson A, Kaczorowska A-K, Adalsteinsson BT, et al. Going to extremes - a metagenomic journey into the dark matter of life. FEMS microbiology letters. 2021: fnab067.The Virus-X-Viral Metagenomics for Innovation Value-project was a scientific expedition to explore and exploit uncharted territory of genetic diversity in extreme natural environments such as geothermal hot springs and deep-sea ocean ecosystems. Specifically, the project was set to analyse and exploit viral metagenomes with the ultimate goal of developing new gene products with high innovation value for applications in biotechnology, pharmaceutical, medical, and the life science sectors. Viral gene pool analysis is also essential to obtain fundamental insight into ecosystem dynamics and to investigate how viruses influence the evolution of microbes and multicellular organisms. The Virus-X Consortium, established in 2016, included experts from eight European countries. The unique approach based on high throughput bioinformatics technologies combined with structural and functional studies resulted in the development of a biodiscovery pipeline of significant capacity and scale. The activities within the Virus-X consortium cover the entire range from bioprospecting and methods development in bioinformatics to protein production and characterisation, with the final goal of translating our results into new products for the bioeconomy. The significant impact the consortium made in all of these areas was possible due to the successful cooperation between expert teams that worked together to solve a complex scientific problem using state-of-the-art technologies as well as developing novel tools to explore the virosphere, widely considered as the last great frontier of life. © The Author(s) 2021. Published by Oxford University Press on behalf of FEMS