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Protease activities in the chloroplast capable of cleaving an LHCII N-terminal peptide

Forsberg, Jens; Ström, Jörgen LU ; Kieselbach, T; Larsson, H; Alexciev, K; Engstrom, A and Åkerlund, Hans-Erik LU (2005) In Physiologia Plantarum 123(1). p.21-29
Abstract
Two protease activities of pea chloroplasts, one located in the stroma and the other associated to the thylakoid membrane, are described. Both proteases catalyse the endo-proteolytic cleavage of a peptide corresponding to the N-terminal loop and the first turn in helix-B of light-harvesting complex II (Lhcb1 from pea). The stromal protease cleaves preferentially on the carboxy-side of glutamic acid residues. Inhibitor studies indicate that this protease is a serine-type protease. The protease was partially purified and could be correlated to a 95-kDa polypeptide band on SDS-polyacrylamide gels. The 95 kDa protein was partially sequenced and showed similarity to an to an 'unknown protein' from A. thaliana (in the NCBI public database) as... (More)
Two protease activities of pea chloroplasts, one located in the stroma and the other associated to the thylakoid membrane, are described. Both proteases catalyse the endo-proteolytic cleavage of a peptide corresponding to the N-terminal loop and the first turn in helix-B of light-harvesting complex II (Lhcb1 from pea). The stromal protease cleaves preferentially on the carboxy-side of glutamic acid residues. Inhibitor studies indicate that this protease is a serine-type protease. The protease was partially purified and could be correlated to a 95-kDa polypeptide band on SDS-polyacrylamide gels. The 95 kDa protein was partially sequenced and showed similarity to an to an 'unknown protein' from A. thaliana (in the NCBI public database) as well as to a glutamyl endopeptidase purified from crude extract of cucumber leaves. It is concluded that the stromal protease is a chloroplast glutamyl endopeptidase (cGEP). The protease localized in the thylakoid membrane, cleaved the peptide at only one site, close to its N terminus. The activity of the thylakoid-associated protease was found to be drastically increased in the presence of the reducing agent 1,4-dithiothreitol. Inhibitor studies suggest that this protease is a cysteine- or serine-type protease. The possible roles of these proteases in the regulation of photosynthetic electron transport and in the chloroplast homeostasis are discussed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physiologia Plantarum
volume
123
issue
1
pages
21 - 29
publisher
Wiley Online Library
external identifiers
  • wos:000226428300003
  • scopus:13244275341
ISSN
0031-9317
DOI
10.1111/j.1399-3054.2005.00441.x
language
English
LU publication?
yes
id
12e393ed-dfd7-40c7-a337-b62233ffffca (old id 152502)
date added to LUP
2007-07-05 09:21:10
date last changed
2017-09-17 07:06:29
@article{12e393ed-dfd7-40c7-a337-b62233ffffca,
  abstract     = {Two protease activities of pea chloroplasts, one located in the stroma and the other associated to the thylakoid membrane, are described. Both proteases catalyse the endo-proteolytic cleavage of a peptide corresponding to the N-terminal loop and the first turn in helix-B of light-harvesting complex II (Lhcb1 from pea). The stromal protease cleaves preferentially on the carboxy-side of glutamic acid residues. Inhibitor studies indicate that this protease is a serine-type protease. The protease was partially purified and could be correlated to a 95-kDa polypeptide band on SDS-polyacrylamide gels. The 95 kDa protein was partially sequenced and showed similarity to an to an 'unknown protein' from A. thaliana (in the NCBI public database) as well as to a glutamyl endopeptidase purified from crude extract of cucumber leaves. It is concluded that the stromal protease is a chloroplast glutamyl endopeptidase (cGEP). The protease localized in the thylakoid membrane, cleaved the peptide at only one site, close to its N terminus. The activity of the thylakoid-associated protease was found to be drastically increased in the presence of the reducing agent 1,4-dithiothreitol. Inhibitor studies suggest that this protease is a cysteine- or serine-type protease. The possible roles of these proteases in the regulation of photosynthetic electron transport and in the chloroplast homeostasis are discussed.},
  author       = {Forsberg, Jens and Ström, Jörgen and Kieselbach, T and Larsson, H and Alexciev, K and Engstrom, A and Åkerlund, Hans-Erik},
  issn         = {0031-9317},
  language     = {eng},
  number       = {1},
  pages        = {21--29},
  publisher    = {Wiley Online Library},
  series       = {Physiologia Plantarum},
  title        = {Protease activities in the chloroplast capable of cleaving an LHCII N-terminal peptide},
  url          = {http://dx.doi.org/10.1111/j.1399-3054.2005.00441.x},
  volume       = {123},
  year         = {2005},
}