Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Anionic Lipid Binding to the Foreign Protein MGS Provides a Tight Coupling between Phospholipid Synthesis and Protein Overexpression in Escherichia coli
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
Show others and affiliations
2013 (English)In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 52, no 33, 5533-5544 p.Article in journal (Refereed) Published
Abstract [en]

Certain membrane proteins involved in lipid synthesis can induce formation of new intracellular membranes in Escherichia coli, i.e., intracellular vesicles. Among those, the foreign monotopic glycosyltransferase MGS from Acholeplasma laidlawii triggers such massive lipid synthesis when overexpressed. To examine the mechanism behind the increased lipid synthesis, we investigated the lipid binding properties of MGS in vivo together with the correlation between lipid synthesis and MGS overexpression levels. A good correlation between produced lipid quantities and overexpressed MGS protein was observed when standard LB medium was supplemented with four different lipid precursors that have significant roles in the lipid biosynthesis pathway. Interestingly, this correlation was highest concerning anionic lipid production and at the same time dependent on the selective binding of anionic lipid molecules by MGS. A selective interaction with anionic lipids was also observed in vitro by P-31 NMR binding studies using bicelles prepared with E. coli lipids. The results clearly demonstrate that the discriminative withdrawal of anionic lipids, especially phosphatidylglycerol, from the membrane through MGS binding triggers an in vivo signal for cells to create a feed-forward stimulation of lipid synthesis in E. coil. By this mechanism, cells can produce more membrane surface in order to accommodate excessively produced MGS molecules, which results in an interdependent cycle of lipid and MGS protein synthesis.

Place, publisher, year, edition, pages
2013. Vol. 52, no 33, 5533-5544 p.
National Category
Biochemistry and Molecular Biology
Research subject
Biochemistry; Biophysics
Identifiers
URN: urn:nbn:se:su:diva-93756DOI: 10.1021/bi400616nISI: 000323471900005OAI: oai:DiVA.org:su-93756DiVA: diva2:650165
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Note

AuthorCount:9;

Available from: 2013-09-20 Created: 2013-09-16 Last updated: 2017-12-06Bibliographically approved
In thesis
1. Exploring the Interplay of Lipids and Membrane Proteins
Open this publication in new window or tab >>Exploring the Interplay of Lipids and Membrane Proteins
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The interplay between lipids and membrane proteins is known to affect membrane protein topology and thus have significant effect (control) on their functions. In this PhD thesis, the influence of lipids on the membrane protein function was studied using three different membrane protein models.

A monotopic membrane protein, monoglucosyldiacylglyecerol synthase (MGS) from Acholeplasma laidlawii is known to induce intracellular vesicles when expressed in Escherichia coli. The mechanism leading to this unusual phenomenon was investigated by various biochemical and biophysical techniques. The results indicated a doubling of lipid synthesis in the cell, which was triggered by the selective binding of MGS to anionic lipids. Multivariate data analysis revealed a good correlation with MGS production. Furthermore, preferential anionic lipid sequestering by MGS was shown to induce a different fatty acid modeling of E. coli membranes. The roles of specific lipid binding and the probable mechanism leading to intracellular vesicle formation were also investigated.

As a second model, a MGS homolog from Synechocystis sp. PCC6803 was selected. MgdA is an integral membrane protein with multiple transmembrane helices and a unique membrane topology. The influence of different type of lipids on MgdA activity was tested with different membrane fractions of Synechocystis. Results indicated a very distinct profile compared to Acholeplasma laidlawii MGS. SQDG, an anionic lipid was found to be the species of the membrane that increased the MgdA activity 7-fold whereas two other lipids (PG and PE) had only minor effects on MgdA. Additionally, a working model of MgdA for the biosynthesis and flow of sugar lipids between Synechocystis membranes was proposed.

The last model system was another integral membrane protein with a distinct structure but also a different function. The envelope stress sensor, CpxA and its interaction with E. coli membranes were studied. CpxA autophosphorylation activity was found to be positively regulated by phosphatidylethanolamine and negatively by anionic lipids. In contrast, phosphorylation of CpxR by CpxA revealed to be increased with PG but inhibited by CL. Non-bilayer lipids had a negative impact on CpxA phosphotransfer activity.

Taken together, these studies provide a better understanding of the significance of the interplay of lipids and model membrane proteins discussed here.

Place, publisher, year, edition, pages
Stockholm: Department of Biochemistry and Biophysics, Stockholm University, 2014. 69 p.
Keyword
Membrane lipids, membrane proteins, anionic lipids, membrane remodeling, intracellular vesicles, model membrane systems, glycosyltransferase, Escherichia coli, lipid composition, fatty acid modification, membrane curvature, bacterial homeoviscous adaptation
National Category
Biological Sciences
Research subject
Biochemistry
Identifiers
urn:nbn:se:su:diva-102675 (URN)978-91-7447-882-2 (ISBN)
Public defence
2014-05-16, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 16 B, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Swedish Foundation for Strategic Research Swedish Research Council
Available from: 2014-04-24 Created: 2014-04-14 Last updated: 2015-03-31Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Ariöz, CandanYe, Weihuaal Bakali, AminLiebau, JobstGötzke, HansjörgBarth, AndreasMäler, Lena
By organisation
Department of Biochemistry and Biophysics
In the same journal
Biochemistry
Biochemistry and Molecular Biology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 95 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf