Inhibition by 4-hydroxynonenal (HNE) of Ca2+ transport by SERCA1a: low concentrations of HNE open protein-mediated leaks in the membrane

Hortigon-Vinagre, M. P. , Chardonnet, S., Montigny, C., Gutiérrez-Martín, Y., Champeil, P. and Henao, F. (2011) Inhibition by 4-hydroxynonenal (HNE) of Ca2+ transport by SERCA1a: low concentrations of HNE open protein-mediated leaks in the membrane. Free Radical Biology and Medicine, 50(2), pp. 323-336. (doi: 10.1016/j.freeradbiomed.2010.11.017) (PMID:21109002)

Abstract

Exposure of sarcoplasmic reticulum membranes to 4-hydroxy-2-nonenal (HNE) resulted in inhibition of the maximal ATPase activity and Ca2+ transport ability of SERCA1a, the Ca2+ pump in these membranes. The concomitant presence of ATP significantly protected SERCA1a ATPase activity from inhibition. ATP binding and phosphoenzyme formation from ATP were reduced after treatment with HNE, whereas Ca2+ binding to the high-affinity sites was altered to a lower extent. HNE reacted with SH groups, some of which were identified by MALDI-TOF mass spectrometry, and competition studies with FITC indicated that HNE also reacted with Lys515 within the nucleotide binding pocket of SERCA1a. A remarkable fact was that both the steady-state ability of SR vesicles to sequester Ca2+ and the ATPase activity of SR membranes in the absence of added ionophore or detergent were sensitive to concentrations of HNE much smaller than those that affected the maximal ATPase activity of SERCA1a. This was due to an increase in the passive permeability of HNE-treated SR vesicles to Ca2+, an increase in permeability that did not arise from alteration of the lipid component of these vesicles. Judging from immunodetection with an anti-HNE antibody, this HNE-dependent increase in permeability probably arose from modification of proteins of about 150–160 kDa, present in very low abundance in longitudinal SR membranes (and in slightly larger abundance in SR terminal cisternae). HNE-induced promotion, via these proteins, of Ca2+ leakage pathways might be involved in the general toxic effects of HNE.

• Item Type: Articles
• Additional Information: This work has been funded in part by Grant PRI06A132 from the Consejería de Infraestructuras y Desarrollo Tecnológico de la Junta de Extremadura. M.P.H.V. is the recipient of a Predoctoral Fellowship of the Junta de Extremadura. The stay in Saclay of María P. HortigónVinagre was supported by a fellowship from the Junta de Extremadura (GRU09056) and by CNRS and CEA.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hortigon, Dr Maria
• Authors: Hortigon-Vinagre, M. P., Chardonnet, S., Montigny, C., Gutiérrez-Martín, Y., Champeil, P., and Henao, F.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
• Journal Name: Free Radical Biology and Medicine
• Publisher: Elsevier
• ISSN: 0891-5849
• ISSN (Online): 1873-4596