We recently documented the expression of a novel human mRNA variant encoding a yet uncharacterized SERCA [SR (sarcoplasmic reticulum)/ER (endoplasmic reticulum) Ca2+-ATPase] protein, SERCA2c [Gélébart, Martin, Enouf and Papp (2003) Biochem. Biophys. Res. Commun. 303, 676–684]. In the present study, we have analysed the expression and functional characteristics of SERCA2c relative to SERCA2a and SERCA2b isoforms upon their stable heterologous expression in HEK-293 cells (human embryonic kidney 293 cells). All SERCA2 proteins induced an increased Ca2+ content in the ER of intact transfected cells. In microsomes prepared from transfected cells, SERCA2c showed a lower apparent affinity for cytosolic Ca2+ than SERCA2a and a catalytic turnover rate similar to SERCA2b. We further demonstrated the expression of the endogenous SERCA2c protein in protein lysates isolated from heart left ventricles using a newly generated SERCA2c-specific antibody. Relative to the known uniform distribution of SERCA2a and SERCA2b in cardiomyocytes of the left ventricle tissue, SERCA2c was only detected in a confined area of cardiomyocytes, in close proximity to the sarcolemma. This finding led us to explore the expression of the presently known cardiac Ca2+-ATPase isoforms in heart failure. Comparative expression of SERCAs and PMCAs (plasma-membrane Ca2+-ATPases) was performed in four nonfailing hearts and five failing hearts displaying mixed cardiomyopathy and idiopathic dilated cardiomyopathies. Relative to normal subjects, cardiomyopathic patients express more PMCAs than SERCA2 proteins. Interestingly, SERCA2c expression was significantly increased (166±26%) in one patient. Taken together, these results demonstrate the expression of the novel SERCA2c isoform in the heart and may point to a still unrecognized role of PMCAs in cardiomyopathies.
Skip Nav Destination
Article navigation
April 2006
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkEditorial Board
Research Article|
March 28 2006
Ca2+-ATPases in non-failing and failing heart: evidence for a novel cardiac sarco/endoplasmic reticulum Ca2+-ATPase 2 isoform (SERCA2c)
Saoussen Dally;
Saoussen Dally
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Raymonde Bredoux;
Raymonde Bredoux
1
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Elisabeth Corvazier;
Elisabeth Corvazier
1
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Jens P. Andersen;
Jens P. Andersen
†Department of Physiology, Institute of Physiology and Biophysics, University of Aarhus, Aarhus, Denmark
Search for other works by this author on:
Johannes D. Clausen;
Johannes D. Clausen
†Department of Physiology, Institute of Physiology and Biophysics, University of Aarhus, Aarhus, Denmark
Search for other works by this author on:
Leonard Dode;
Leonard Dode
‡Laboratory of Physiology, Catholic University of Leuven, Leuven, Belgium
Search for other works by this author on:
Mohammed Fanchaouy;
Mohammed Fanchaouy
2
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Pascal Gelebart;
Pascal Gelebart
3
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Virginie Monceau;
Virginie Monceau
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Frederica Del Monte;
Frederica Del Monte
§Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, U.S.A.
Search for other works by this author on:
Judith K. Gwathmey;
Judith K. Gwathmey
§Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, U.S.A.
Search for other works by this author on:
Roger Hajjar;
Roger Hajjar
§Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, U.S.A.
Search for other works by this author on:
Chiraz Chaabane;
Chiraz Chaabane
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Régis Bobe;
Régis Bobe
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
Search for other works by this author on:
Aly Raies;
Aly Raies
∥Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Tunisia
Search for other works by this author on:
Jocelyne Enouf
Jocelyne Enouf
4
*INSERM U689, IFR139, Hôpital Lariboisière, 8 Rue Guy Patin, 75475 Paris Cedex 10, France
4To whom correspondence should be addressed (email jocelyne.enouf@larib.inserm.fr).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
August 30 2005
Revision Received:
December 08 2005
Accepted:
January 11 2006
Accepted Manuscript online:
January 11 2006
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London
2006
Biochem J (2006) 395 (2): 249–258.
Article history
Received:
August 30 2005
Revision Received:
December 08 2005
Accepted:
January 11 2006
Accepted Manuscript online:
January 11 2006
Citation
Saoussen Dally, Raymonde Bredoux, Elisabeth Corvazier, Jens P. Andersen, Johannes D. Clausen, Leonard Dode, Mohammed Fanchaouy, Pascal Gelebart, Virginie Monceau, Frederica Del Monte, Judith K. Gwathmey, Roger Hajjar, Chiraz Chaabane, Régis Bobe, Aly Raies, Jocelyne Enouf; Ca2+-ATPases in non-failing and failing heart: evidence for a novel cardiac sarco/endoplasmic reticulum Ca2+-ATPase 2 isoform (SERCA2c). Biochem J 15 April 2006; 395 (2): 249–258. doi: https://doi.org/10.1042/BJ20051427
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.