Search

Your search keyword '"Stoll, Britta"' showing total 20 results
Start Over Author "Stoll, Britta"
20 results on '"Stoll, Britta"'

1. Iron starvation results in up-regulation of a probable Haloferax volcanii siderophore transporter.

Author

Sailer, Anna-Lena, Jevtic, Zivojin, Stoll, Britta, Wörtz, Julia, Sharma, Kundan, Urlaub, Henning, Dyall-Smith, Mike, Pfeiffer, Friedhelm, Marchfelder, Anita, and Lenz, Christof

Subjects
LIBRARY acquisitions, GROWTH disorders, MASS spectrometry, MOLECULAR docking, CELL morphology
Abstract

The response of the haloarchaeal model organism Haloferax volcanii to iron starvation was analyzed at the proteome level by data-independent acquisition mass spectrometry. Cells grown in minimal medium with normal iron levels were compared to those grown under low iron conditions, with samples being separated into membrane and cytoplasmic fractions in order to focus on import/export processes which are frequently associated with metal homeostasis. Iron starvation not only caused a severe retardation of growth but also altered the levels of many proteins. Using a comprehensive annotated spectral library and data-independent acquisition mass spectrometry (DIA-MS), we found that iron starvation resulted in significant changes to both the membrane and the soluble proteomes of Hfx. volcanii. The most affected protein is the RND family permease HVO_A0467, which is 44-fold enriched in cells grown under iron starvation. The gene HVO_A0467 can be deleted suggesting that it is not essential under standard conditions. Compared to wild type cells the deletion strain shows only slight changes in growth and cell morphologies show no differences. Molecular docking predictions indicated that HVO_A0467 may be an exporter of the siderophore schizokinen for which a potential biosynthesis cluster is encoded in the Hfx. volcanii genome. Together, these findings confirm the importance of iron for archaeal cells and suggest HVO_0467 as a siderophore exporter. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

7. The nuts and bolts of the Haloferax CRISPR-Cas system I-B

Author

Maier, Lisa-Katharina, primary, Stachler, Aris-Edda, additional, Brendel, Jutta, additional, Stoll, Britta, additional, Fischer, Susan, additional, Haas, Karina A., additional, Schwarz, Thandi S., additional, Alkhnbashi, Omer S., additional, Sharma, Kundan, additional, Urlaub, Henning, additional, Backofen, Rolf, additional, Gophna, Uri, additional, and Marchfelder, Anita, additional

Published
2018
Full Text
View/download PDF

8. The nuts and bolts of the Haloferax CRISPR-Cas system I-B.

Author

Maier, Lisa-Katharina, Stachler, Aris-Edda, Brendel, Jutta, Stoll, Britta, Fischer, Susan, Haas, Karina A., Schwarz, Thandi S., Alkhnbashi, Omer S., Sharma, Kundan, Urlaub, Henning, Backofen, Rolf, Gophna, Uri, and Marchfelder, Anita

Abstract

Invading genetic elements pose a constant threat to prokaryotic survival, requiring an effective defence. Eleven years ago, the arsenal of known defence mechanisms was expanded by the discovery of the CRISPR-Cas system. Although CRISPR-Cas is present in the majority of archaea, research often focuses on bacterial models. Here, we provide a perspective based on insights gained studying CRISPR-Cas system I-B of the archaeon Haloferax volcanii. The system relies on more than 50 different crRNAs, whose stability and maintenance critically depend on the proteins Cas5 and Cas7, which bind the crRNA and form the Cascade complex. The interference machinery requires a seed sequence and can interact with multiple PAM sequences. H. volcanii stands out as the first example of an organism that can tolerate autoimmunity via the CRISPR-Cas system while maintaining a constitutively active system. In addition, the H. volcanii system was successfully developed into a tool for gene regulation. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

9. Analyse des prokaryotischen Immunsystems CRISPR/Cas Typ I-B im archaealen Modellorganismus Haloferax volcanii

Author

Stoll, Britta

Subjects
Prokaryoten, CRISPR/Cas, DDC 570 / Life sciences, ddc:570, Prokaryotisches Immunsystem, Prokaryotes, Haloferax volcanii
Abstract

Prokaryotes develop various strategies to protect themselves against invasive mobile genetic elements. One of these strategies is the adaptive and heritable CRISPR/Cas-system. Since the halophilic organism Haloferax volcanii possesses only one CRISPR/Cas-system of type I-B with a relatively low degree of complexity it is well-suited for the investigation of this prokaryotic immune system. Additionally, its genome is completely sequenced and various methods for transformation, genetic manipulation and selection are available. The aim of this work is to gain insights into the mechanism and the function of the protein components of the Haloferax CRISPR/Cas-system. The results show, that none of the investigated Cas-proteins is required for regular growth of the organism. However, Cas6 and Cas7 are essential for the production of mature and functional crRNA. Focussing on the investigation of the Haloferax Cas7 protein reveals its indirect involvement in the processing of pre-crRNA. Two models are developed to describe this involvement. In both approaches, Cas7 binds and protects crRNA and contributes to the construction of the effector-complex "cascade". The two models differ with respect to the timing of the pre-crRNA processing. In the first model, the processing takes place in the cascade-complex while in the second model this step is carried out in a subcomplex consisting of Cas5, Cas6 and Cas7 before the effector-complex is fully assembled. Related to this, the existence of a stable Cas5/Cas7-subcomplex and a possible cascade-like complex is demonstrated. The involvement of the Cas7 protein in the interference reaction results from the interaction with other protein components of the cascade complex. Efficiency analysis of different protospacers show that older spacers located at the end of the respective loci are not functional. Also, the combination and mutual influence of several factors is likely crucial for a successful defense reaction of invading plasmids.

Published
2014
Full Text
View/download PDF

10. The nuts and bolts of the HaloferaxCRISPR-Cas system I-B

Author

Maier, Lisa-Katharina, Stachler, Aris-Edda, Brendel, Jutta, Stoll, Britta, Fischer, Susan, Haas, Karina A., Schwarz, Thandi S., Alkhnbashi, Omer S., Sharma, Kundan, Urlaub, Henning, Backofen, Rolf, Gophna, Uri, and Marchfelder, Anita

Abstract

ABSTRACTInvading genetic elements pose a constant threat to prokaryotic survival, requiring an effective defence. Eleven years ago, the arsenal of known defence mechanisms was expanded by the discovery of the CRISPR-Cas system. Although CRISPR-Cas is present in the majority of archaea, research often focuses on bacterial models. Here, we provide a perspective based on insights gained studying CRISPR-Cas system I-B of the archaeon Haloferax volcanii. The system relies on more than 50 different crRNAs, whose stability and maintenance critically depend on the proteins Cas5 and Cas7, which bind the crRNA and form the Cascade complex. The interference machinery requires a seed sequence and can interact with multiple PAM sequences. H. volcaniistands out as the first example of an organism that can tolerate autoimmunity via the CRISPR-Cas system while maintaining a constitutively active system. In addition, the H. volcaniisystem was successfully developed into a tool for gene regulation.

Published
2019
Full Text
View/download PDF

11. The role of Cas8 in type I CRISPR interference

Author

Cass, Simon D.B., primary, Haas, Karina A., additional, Stoll, Britta, additional, Alkhnbashi, Omer S., additional, Sharma, Kundan, additional, Urlaub, Henning, additional, Backofen, Rolf, additional, Marchfelder, Anita, additional, and Bolt, Edward L., additional

Published
2015
Full Text
View/download PDF

12. A Complex of Cas Proteins 5, 6, and 7 Is Required for the Biogenesis and Stability of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-derived RNAs (crRNAs) in Haloferax volcanii

Author

Brendel, Jutta, primary, Stoll, Britta, additional, Lange, Sita J., additional, Sharma, Kundan, additional, Lenz, Christof, additional, Stachler, Aris-Edda, additional, Maier, Lisa-Katharina, additional, Richter, Hagen, additional, Nickel, Lisa, additional, Schmitz, Ruth A., additional, Randau, Lennart, additional, Allers, Thorsten, additional, Urlaub, Henning, additional, Backofen, Rolf, additional, and Marchfelder, Anita, additional

Published
2014
Full Text
View/download PDF

16. The immune system of halophilic archaea

Author

Maier, Lisa-Katharina, primary, Fischer, Susan M, additional, Stoll, Britta, additional, Brendel, Jutta, additional, Pfeiffer, Friedhelm, additional, Dyall-Smith, Mike, additional, and Marchfelder, Anita, additional

Published
2012
Full Text
View/download PDF

20. Essential requirements for the detection and degradation of invaders by the Haloferax volcaniiCRISPR/Cas system I-B

Author

Maier, Lisa-Katharina, Lange, Sita J., Stoll, Britta, Haas, Karina A., Fischer, Susan M, Fischer, Eike, Duchardt-Ferner, Elke, Wöhnert, Jens, Backofen, Rolf, and Marchfelder, Anita

Abstract

To fend off foreign genetic elements, prokaryotes have developed several defense systems. The most recently discovered defense system, CRISPR/Cas, is sequence-specific, adaptive and heritable. The two central components of this system are the Cas proteins and the CRISPR RNA. The latter consists of repeat sequences that are interspersed with spacer sequences. The CRISPR locus is transcribed into a precursor RNA that is subsequently processed into short crRNAs. CRISPR/Cas systems have been identified in bacteria and archaea, and data show that many variations of this system exist. We analyzed the requirements for a successful defense reaction in the halophilic archaeon Haloferax volcanii. Haloferaxencodes a CRISPR/Cas system of the I-B subtype, about which very little is known. Analysis of the mature crRNAs revealed that they contain a spacer as their central element, which is preceded by an eight-nucleotide-long 5′ handle that originates from the upstream repeat. The repeat sequences have the potential to fold into a minimal stem loop. Sequencing of the crRNA population indicated that not all of the spacers that are encoded by the three CRISPR loci are present in the same abundance. By challenging Haloferaxwith an invader plasmid, we demonstrated that the interaction of the crRNA with the invader DNA requires a 10-nucleotide-long seed sequence. In addition, we found that not all of the crRNAs from the three CRISPR loci are effective at triggering the degradation of invader plasmids. The interference does not seem to be influenced by the copy number of the invader plasmid.

Published
2013
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results