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
Binding of divalent cations is essential for the activity of the organellar peptidasome in Arabidopsis thaliana, AtPreP.
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.
2009 (English)In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 583, no 17, 2727-33 p.Article in journal (Refereed) Published
Abstract [en]

The dual-targeted mitochondrial and chloroplastic zinc metallooligopeptidase from Arabidopsis, AtPreP, functions as a peptidasome that degrades targeting peptides and other small unstructured peptides. In addition to Zn located in the catalytic site, AtPreP also contains two Mg-binding sites. We have investigated the role of Mg-binding using AtPreP variants, in which one or both sites were rendered unable to bind Mg(2+). Our results show that metal binding besides that of the active site is crucial for AtPreP proteolysis, particularly the inner site appears essential for normal proteolytic function. This is also supported by its evolutionary conservation among all plant species of PreP.

Place, publisher, year, edition, pages
2009. Vol. 583, no 17, 2727-33 p.
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Identifiers
URN: urn:nbn:se:su:diva-34682DOI: 10.1016/j.febslet.2009.07.040ISI: 000270149800005PubMedID: 19646442OAI: oai:DiVA.org:su-34682DiVA: diva2:285275
Available from: 2010-01-11 Created: 2010-01-11 Last updated: 2017-12-12Bibliographically approved
In thesis
1. Functional and structural studies of the Presequence protease, PreP
Open this publication in new window or tab >>Functional and structural studies of the Presequence protease, PreP
2014 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

AtPreP (Arabidopsis thaliana Presequence Protease) is a zink metallooligopeptidase that is dually targeted to both mitochondria and chloroplasts. In these organelles it functions as a peptidasome that degrades the N-terminal targeting peptides that are cleaved off from the mature protein after protein import, as well as other unstructured peptides. In A. thaliana there are two isoforms of PreP, AtPreP1 and AtPreP2. 

We have performed characterization studies of single and double prep knockout plants. Immunoblot analysis revealed that both PreP isoforms are expressed in all tissues with highest expression levels in flowers and siliques. Furthermore, AtPreP1 was shown to be the most abundant isoform of the two. When comparing phenotype, the atprep2 mutant was similar to wild type, whereas the atprep1 mutant had a slight pale-green phenotype in the early developmental stages. The atprep1 atprep2 double knockout plants showed a chlorotic phenotype in true leaves, especially prominent during the early developmental stages. When analysing the first true leaves of double knockout plants, we found a significant decrease in chlorophyll a and b content. Mitochondrial respiratory rates measurements showed partially uncoupled mitochondria. Ultrastructure analysis using electron microscopy on double knockout plants showed aberrant chloroplasts with altered grana stacking and clearly fewer starch granules. Older plants showed less altered  phenotype, although there was a significant decrease in the accumulated biomass of about 40% compared to wild type. Peptidolytic activity studies showed no sign of compensatory mechanisms in the absence of AtPreP in mitochondria; in contrast we found a peptidolytic activity in the chloroplast membranes not related to AtPreP.

In addition to zinc located in the catalytic site, crystallographic data revealed two Mg-binding sites in the AtPreP structure. To further investigate the role of these Mg-binding sites, we have made AtPreP variants that are unable to bind metal ions. Our data shows that one of these sites located close to the catalytic site is important for the activity of AtPreP.

We also measured proteolytic activity of four human PreP-SNP variants and observed that the activity of all the hPreP-SNPs variants was lower; especially the hPreP-SNP (A525D) variant that displayed only 20-30 % of wild type activity. Interestingly, the activity was fully restored for all SNP-variants by addition of Mg2+

Place, publisher, year, edition, pages
Stockholm: Department of Biochemistry and Biophysics, Stockholm University, 2014. 37 p.
Keyword
Presequence Protease, PreP, AtPreP, hPreP
National Category
Biochemistry and Molecular Biology
Research subject
Biochemistry
Identifiers
urn:nbn:se:su:diva-102310 (URN)
Presentation
2014-04-24, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrheniusväg 16 B, Stockholm, 15:00 (English)
Opponent
Supervisors
Available from: 2014-04-01 Created: 2014-03-31 Last updated: 2014-04-01Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Bäckman, Hans GEneqvist, ThereseGlaser, Elzbieta
By organisation
Department of Biochemistry and Biophysics
In the same journal
FEBS Letters
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 46 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