Overexpression of the Ca2+-binding protein calreticulin in the endoplasmic reticulum improves growth of tobacco cell suspensions (Nicotiana tabacum) in high-Ca2+ medium
(2005) In Physiologia Plantarum 123(1). p.92-99- Abstract
- Calreticulin (CRT) is a eukaryotic, highly conserved, Ca2+-binding protein predominantly located in the endoplasmic reticulum (ER) lumen. In addition to being involved in the regulation of cellular Ca2+, calreticulin is a key quality control element during protein folding in the ER lumen. Tobacco (Nicotiana tabacum L.) suspension cells overexpressing a maize CRT (CRT1a) were used here to examine the properties of CRT in growing plant cells with respect to stress exposure. The endogenous CRT gene was induced rapidly after subculturing of the cells to new medium. In accordance, the CRT protein levels increased, peaking at days 3-4. At day 5, when the CRT transcript levels had levelled off, a further increase in endogenous CRT expression was... (More)
- Calreticulin (CRT) is a eukaryotic, highly conserved, Ca2+-binding protein predominantly located in the endoplasmic reticulum (ER) lumen. In addition to being involved in the regulation of cellular Ca2+, calreticulin is a key quality control element during protein folding in the ER lumen. Tobacco (Nicotiana tabacum L.) suspension cells overexpressing a maize CRT (CRT1a) were used here to examine the properties of CRT in growing plant cells with respect to stress exposure. The endogenous CRT gene was induced rapidly after subculturing of the cells to new medium. In accordance, the CRT protein levels increased, peaking at days 3-4. At day 5, when the CRT transcript levels had levelled off, a further increase in endogenous CRT expression was obtained when the cells were treated with excess Ca2+ or the N-linked glycosylation inhibitor tunicamycin. Whereas the response to Ca2+ occurred within 30 min, the induction by tunicamycin took several hours to be established. Transforming tobacco cells with maize CRT1a, under a constitutive mannopine synthase promoter, resulted in a stable level of expressed CRT1a during the growth cycle compared with endogenous CRT. The CRTs showed differences in attached glycans, but both contained the high mannose-rich-type glycans characteristic of ER proteins. In agreement with an ER location, both tobacco CRT and the transgene product CRT1a codistributed with the ER marker NADH cytochrome c reductase after density gradient centrifugation of microsomal fractions from tobacco cells. Increased production of CRT, as was obtained in the transgenic tobacco cell lines, made cells more tolerant than wild-type cells to high Ca2+ during growth. These data suggest that overexpression of CRT1a in plant cells results in a more efficient calcium buffering capacity in the ER. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/152511
- author
- Christensen, Anna LU ; Persson, Staffan LU ; Love, J ; Boss, W F ; Widell, Susanne LU and Sommarin, Marianne LU
- organization
- publishing date
- 2005
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physiologia Plantarum
- volume
- 123
- issue
- 1
- pages
- 92 - 99
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- wos:000226428300011
- scopus:13244294159
- ISSN
- 0031-9317
- DOI
- 10.1111/j.1399-3054.2004.00434.x
- language
- English
- LU publication?
- yes
- id
- 6f0b8557-1eb9-467e-9bff-7eb47a918cd5 (old id 152511)
- date added to LUP
- 2016-04-01 16:16:41
- date last changed
- 2022-01-28 18:34:01
@article{6f0b8557-1eb9-467e-9bff-7eb47a918cd5,
abstract = {{Calreticulin (CRT) is a eukaryotic, highly conserved, Ca2+-binding protein predominantly located in the endoplasmic reticulum (ER) lumen. In addition to being involved in the regulation of cellular Ca2+, calreticulin is a key quality control element during protein folding in the ER lumen. Tobacco (Nicotiana tabacum L.) suspension cells overexpressing a maize CRT (CRT1a) were used here to examine the properties of CRT in growing plant cells with respect to stress exposure. The endogenous CRT gene was induced rapidly after subculturing of the cells to new medium. In accordance, the CRT protein levels increased, peaking at days 3-4. At day 5, when the CRT transcript levels had levelled off, a further increase in endogenous CRT expression was obtained when the cells were treated with excess Ca2+ or the N-linked glycosylation inhibitor tunicamycin. Whereas the response to Ca2+ occurred within 30 min, the induction by tunicamycin took several hours to be established. Transforming tobacco cells with maize CRT1a, under a constitutive mannopine synthase promoter, resulted in a stable level of expressed CRT1a during the growth cycle compared with endogenous CRT. The CRTs showed differences in attached glycans, but both contained the high mannose-rich-type glycans characteristic of ER proteins. In agreement with an ER location, both tobacco CRT and the transgene product CRT1a codistributed with the ER marker NADH cytochrome c reductase after density gradient centrifugation of microsomal fractions from tobacco cells. Increased production of CRT, as was obtained in the transgenic tobacco cell lines, made cells more tolerant than wild-type cells to high Ca2+ during growth. These data suggest that overexpression of CRT1a in plant cells results in a more efficient calcium buffering capacity in the ER.}},
author = {{Christensen, Anna and Persson, Staffan and Love, J and Boss, W F and Widell, Susanne and Sommarin, Marianne}},
issn = {{0031-9317}},
language = {{eng}},
number = {{1}},
pages = {{92--99}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Physiologia Plantarum}},
title = {{Overexpression of the Ca2+-binding protein calreticulin in the endoplasmic reticulum improves growth of tobacco cell suspensions (Nicotiana tabacum) in high-Ca2+ medium}},
url = {{http://dx.doi.org/10.1111/j.1399-3054.2004.00434.x}},
doi = {{10.1111/j.1399-3054.2004.00434.x}},
volume = {{123}},
year = {{2005}},
}