WorldCat Identities

Albers, Sonja-Verena

Overview
Works: 28 works in 33 publications in 2 languages and 233 library holdings
Roles: Author, Other, dgs
Publication Timeline
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Most widely held works by Sonja-Verena Albers
Archaeal Cell Envelope and Surface Structures by Sonja-Verena Albers( )

2 editions published in 2016 in Undetermined and English and held by 153 WorldCat member libraries worldwide

Prokaryotes have a complex cell envelope which has several important functions, including providing a barrier that protects the cytoplasm from the environment. Along with its associated proteinaceous structures, it also ensures cell stability, facilitates motility, mediates adherence to biotic and abiotic surfaces, and facilitates communication with the extracellular environment. Viruses have evolved to take advantage of cell envelope constituents to gain access to the cellular interior as well as for egress from the cell. While many aspects of the biosynthesis and structure of the cell envelope are similar across domains, archaeal cell envelopes have several unique characteristics including, among others, an isoprenoid lipid bilayer, a non-murein-based cell wall, and a unique motility structure, important features that give archaeal cell envelopes characteristics that are significantly different from those of bacterial cell envelopes. Recent analyses have revealed that the cell envelopes of distantly related archaea also display an immense diversity of characteristics. For instance, while many archaea have an S-layer, the subunits of S-layers of various archaeal species, as well as their posttranslational modifications, vary significantly. Moreover, like gram-negative bacteria, recent studies have shown that some archaeal species also have an outer membrane. In this collection of articles, we include contributions that focus on research that has expanded our understanding of the mechanisms underlying the biogenesis and functions of archaeal cell envelopes and their constituent surface structures
Sugar transport in the thermoacidophilic archaeon Sulfolobus solfataricus by Sonja-Verena Albers( Book )

3 editions published in 2001 in English and held by 8 WorldCat member libraries worldwide

Positioning of the motility machinery in halophilic archaea by Zhengqun Li( )

1 edition published in 2019 in English and held by 3 WorldCat member libraries worldwide

Abstract: Bacteria and archaea exhibit tactical behavior and can move up and down chemical gradients. This tactical behavior relies on a motility structure, which is guided by a chemosensory system. Environmental signals are sensed by membrane-inserted chemosensory receptors that are organized in large ordered arrays. While the cellular positioning of the chemotaxis machinery and that of the flagellum have been studied in detail in bacteria, we have little knowledge about the localization of such macromolecular assemblies in archaea. Although the archaeal motility structure, the archaellum, is fundamentally different from the flagellum, archaea have received the chemosensory machinery from bacteria and have connected this system with the archaellum. Here, we applied a combination of time-lapse imaging and fluorescence and electron microscopy using the model euryarchaeon Haloferax volcanii and found that archaella were specifically present at the cell poles of actively dividing rod-shaped cells. The chemosensory arrays also had a polar preference, but in addition, several smaller arrays moved freely in the lateral membranes. In the stationary phase, rod-shaped cells became round and chemosensory arrays were disassembled. The positioning of archaella and that of chemosensory arrays are not interdependent and likely require an independent form of positioning machinery. This work showed that, in the rod-shaped haloarchaeal cells, the positioning of the archaellum and of the chemosensory arrays is regulated in time and in space. These insights into the cellular organization of H. volcanii suggest the presence of an active mechanism responsible for the positioning of macromolecular protein complexes in archaea.<br><br>IMPORTANCE Archaea are ubiquitous single cellular microorganisms that play important ecological roles in nature. The intracellular organization of archaeal cells is among the unresolved mysteries of archaeal biology. With this work, we show that cells of haloarchaea are polarized. The cellular positioning of proteins involved in chemotaxis and motility is spatially and temporally organized in these cells. This suggests the presence of a specific mechanism responsible for the positioning of macromolecular protein complexes in archaea
The phosphatase PP2A interacts with ArnA and ArnB to regulate the oligomeric state and the stability of the ArnA/B complex by Xing Ye( )

1 edition published in 2020 in English and held by 3 WorldCat member libraries worldwide

Abstract: In the crenarchaeon Sulfolobus acidocaldarius, the archaellum, a type-IV pilus like motility structure, is synthesized in response to nutrient starvation. Synthesis of components of the archaellum is controlled by the archaellum regulatory network (arn). Protein phosphorylation plays an important role in this regulatory network since the deletion of several genes encoding protein kinases and the phosphatase PP2A affected cell motility. Several proteins in the archaellum regulatory network can be phosphorylated, however, details of how phosphorylation levels of different components affect archaellum synthesis are still unknown. To identify proteins interacting with the S. acidocaldarius phosphatases PTP and PP2A, co-immunoprecipitation assays coupled to mass spectrometry analysis were performed. Thirty minutes after growth in nutrient starvation medium, especially a conserved putative ATP/GTP binding protein (Saci_1281), a universal stress protein (Saci_0887) and the archaellum regulators ArnA and ArnB were identified as highly abundant interaction proteins of PP2A. The interaction between ArnA, ArnB, and PP2A was further studied. Previous studies showed that the Forkhead-associated domain containing ArnA interacts with von Willebrand type A domain containing ArnB, and that both proteins could be phosphorylated by the kinase ArnC in vitro. The ArnA/B heterodimer was reconstituted from the purified proteins. In complex with ArnA, phosphorylation of ArnB by the ArnC kinase was strongly stimulated and resulted in formation of (ArnA/B)2 and higher oligomeric complexes, while association and dephosphorylation by PP2A resulted in dissociation of these ArnA/B complexes
The role of polyphosphate in motility, adhesion, and biofilm formation in sulfolobales by Alejandra Recalde( )

1 edition published in 2021 in English and held by 3 WorldCat member libraries worldwide

Abstract: Polyphosphates (polyP) are polymers of orthophosphate residues linked by high-energy phosphoanhydride bonds that are important in all domains of life and function in many different processes, including biofilm development. To study the effect of polyP in archaeal biofilm formation, our previously described Sa. solfataricus polyP (−) strain and a new polyP (−) S. acidocaldarius strain generated in this report were used. These two strains lack the polymer due to the overexpression of their respective exopolyphosphatase gene (ppx). Both strains showed a reduction in biofilm formation, decreased motility on semi-solid plates and a diminished adherence to glass surfaces as seen by DAPI (4′,6-diamidino-2-phenylindole) staining using fluorescence microscopy. Even though arlB (encoding the archaellum subunit) was highly upregulated in S. acidocardarius polyP (−), no archaellated cells were observed. These results suggest that polyP might be involved in the regulation of the expression of archaellum components and their assembly, possibly by affecting energy availability, phosphorylation or other phenomena. This is the first evidence indicating polyP affects biofilm formation and other related processes in archaea
Early response of Sulfolobus acidocaldarius to nutrient limitation by Lisa Bischof( )

1 edition published in 2019 in English and held by 3 WorldCat member libraries worldwide

Biofilm formation of mucosa-associated methanoarchaeal strains by Corinna Bang( )

2 editions published in 2014 in English and held by 3 WorldCat member libraries worldwide

Editorial: Archaeal cell envelope and surface structures by Mecky Pohlschröder( )

1 edition published in 2016 in English and held by 3 WorldCat member libraries worldwide

Wie ein rotierender Typ-IV-Pilus Archaeen das Schwimmen beibrachte by Patrick Tripp( )

1 edition published in 2020 in German and held by 3 WorldCat member libraries worldwide

Abstract: Swimming motility in Archaea is mediated by the archaellum, a rotating type IV pilus. Archaellum-based motility is the only known way of active locomotion in Archaea to date. Here, we describe the way of how the archaellum was discovered to be a unique structure in nature and highlight the latest findings on archaellar components
Two membrane-bound transcription factors regulate expression of various type-IV-pili surface structures in Sulfolobus acidocaldarius by Lisa Bischof( )

1 edition published in 2019 in English and held by 3 WorldCat member libraries worldwide

Abstract: In Archaea and Bacteria, gene expression is tightly regulated in response to environmental stimuli. In the thermoacidophilic crenarchaeon Sulfolobus acidocaldarius nutrient limitation induces expression of the archaellum, the archaeal motility structure. This expression is orchestrated by a complex hierarchical network of positive and negative regulators--the archaellum regulatory network (arn). The membrane-bound one-component system ArnR and its paralog ArnR1<br>were recently described as main activators of archaellum expression in S. acidocaldarius. They regulate gene expression of the archaellum operon by targeting the promoter of flaB, encoding the archaellum filament protein. Here we describe a strategy for the isolation and biochemical characterization of these two archaellum regulators. Both regulators are capable of forming oligomers and are<br>phosphorylated by the Ser/Thr kinase ArnC. Apart from binding to pflaB, ArnR but not ArnR1 bound to promoter sequences of aapF and upsX, which encode components of the archaeal adhesive pilus and UV-inducible pili system,<br>demonstrating a regulatory connection between different surface appendages of S. acidocaldarius
Decipering the subunit interaction in the crenarchaeal archaellum by Tomasz Paweł Neiner( )

1 edition published in 2015 in English and held by 3 WorldCat member libraries worldwide

Insights into synthesis and function of KsgA/Dim1-dependent rRNA modifications in archaea by Robert Knüppel( )

1 edition published in 2021 in English and held by 3 WorldCat member libraries worldwide

Abstract: Ribosomes are intricate molecular machines ensuring proper protein synthesis in every cell. Ribosome biogenesis is a complex process which has been intensively analyzed in bacteria and eukaryotes. In contrast, our understanding of the in vivo archaeal ribosome biogenesis pathway remains less characterized. Here, we have analyzed the in vivo role of the almost universally conserved ribosomal RNA dimethyltransferase KsgA/Dim1 homolog in archaea. Our study reveals that KsgA/Dim1-dependent 16S rRNA dimethylation is dispensable for the cellular growth of phylogenetically distant archaea. However, proteomics and functional analyses suggest that archaeal KsgA/Dim1 and its rRNA modification activity (i) influence the expression of a subset of proteins and (ii) contribute to archaeal cellular fitness and adaptation. In addition, our study reveals an unexpected KsgA/Dim1-dependent variability of rRNA modifications within the archaeal phylum. Combining structure-based functional studies across evolutionary divergent organisms, we provide evidence on how rRNA structure sequence variability (re-)shapes the KsgA/Dim1-dependent rRNA modification status. Finally, our results suggest an uncoupling between the KsgA/Dim1-dependent rRNA modification completion and its release from the nascent small ribosomal subunit. Collectively, our study provides additional understandings into principles of molecular functional adaptation, and further evolutionary and mechanistic insights into an almost universally conserved step of ribosome synthesis
SaUspA, the universal stress protein of Sulfolobus acidocaldarius stimulates the activity of the PP2A phosphatase and is involved in growth at high salinity by Xing Ye( )

1 edition published in 2020 in English and held by 3 WorldCat member libraries worldwide

An ascillating MinD protein determines the cellular positioning of the motility machinery in archaea by Phillip Nußbaum( )

1 edition published in 2020 in English and held by 3 WorldCat member libraries worldwide

Corrigendum: The phosphatase PP2A interacts with ArnA and ArnB to regulate the oligomeric state and the stability of the ArnA/B complex by Xing Ye( )

1 edition published in 2020 in English and held by 3 WorldCat member libraries worldwide

Diversity and evolution of type IV pili systems in archaea by Kira S Makarova( )

1 edition published in 2016 in English and held by 3 WorldCat member libraries worldwide

Abstract: Many surface structures in archaea including various types of pili and the archaellum (archaeal flagellum) are homologous to bacterial type IV pili systems (T4P). The T4P consist of multiple proteins, often with poorly conserved sequences, complicating their identification in sequenced genomes. Here we report a comprehensive census of T4P encoded in archaeal genomes using sensitive methods for protein sequence comparison. This analysis confidently identifies as T4P components about 5000 archaeal gene products, 56% of which are currently annotated as hypothetical in public databases. Combining results of this analysis with a comprehensive comparison of genomic neighborhoods of the T4P, we present models of organization of 10 most abundant variants of archaeal T4P. In addition to the differentiation between major and minor pilins, these models include extra components, such as S-layer proteins, adhesins and other membrane and intracellular proteins. For most of these systems, dedicated major pilin families are identified including numerous stand alone major pilin genes of the PilA family. Evidence is presented that secretion ATPases of the T4P and cognate TadC proteins can interact with different pilin sets. Modular evolution of T4P results in combinatorial variability of these systems. Potential regulatory or modulating proteins for the T4P are identified including KaiC family ATPases, vWA domain-containing proteins and the associated MoxR/GvpN ATPase, TFIIB homologs and multiple unrelated transcription regulators some of which are associated specific T4P. Phylogenomic analysis suggests that at least one T4P system was present in the last common ancestor of the extant archaea. Multiple cases of horizontal transfer and lineage-specific duplication of T4P loci were detected. Generally, the T4P of the archaeal TACK superphylum are more diverse and evolve notably faster than those of euryarchaea. The abundance and enormous diversity of T4P in hyperthermophilic archaea present a major enigma. Apparently, fundamental aspects of the biology of hyperthermophiles remain to be elucidated
Analysis of cell-cell bridges in Haloferax volcanii using electron cryo-tomography reveal a continuous cytoplasm and S-layer by Shamphavi Sivabalasarma( )

1 edition published in 2021 in English and held by 2 WorldCat member libraries worldwide

Development of decarboxylases and dehydratases as valuable biocatalysts for the production of fine chemicals by Samuel Sutiono( )

1 edition published in 2021 in English and held by 2 WorldCat member libraries worldwide

 
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Audience level: 0.70 (from 0.61 for Archaeal C ... to 0.97 for Archaeal C ...)

Alternative Names
Albers, Sonja-Verena

Sonja-Verena Albers researcher

Sonja-Verena Albers wetenschapper

Languages
English (21)

German (3)