Work

Expression and localization of estrogen receptor α in the C2C12 murine skeletal muscle cell line

Year: 2008

Type: article

Abstract: The classical model of 17beta-estradiol action has been traditionally described to be mediated by the estrogen receptor (ER) localized exclusively in the nucleus. However, there is increasing functional evidence for extra nuclear localization of ER. We present biochemical, immunological and molecular data supporting mitochondrial-microsomal localization of ER alpha in the C2C12 skeletal muscle cell line. We first established [(3)H]17beta estradiol binding characteristics in whole cells in culture. Specific and saturable [(3)H]17beta estradiol binding sites of high affinity were then detected in mitochondrial fractions (K(d) = 0.43 nM; B(max) = 572 fmol/mg protein). Immunocytological studies revealed that estrogen receptors mainly localize at the mitochondrial and perinuclear level. These results were also confirmed using fluorescent 17beta estradiol-BSA conjugates. The immunoreactivity did not translocate into the nucleus by 17beta-estradiol treatment. Western and Ligand blot approaches corroborated the non-classical localization. Expression and subcellular distribution of ER alpha proteins were confirmed in C2C12 cells transfected with ER alpha siRNA and by RT-PCR employing specific primers. The non-classical distribution of native pools of ER alpha in skeletal muscle cells suggests an alternative mode of ER localization/function.

Source: Journal of Cellular Biochemistry

DOI: 10.1002/jcb.21706

Authors: Lorena Milanesi, Ana Russo de Boland, Ricardo Boland

Institution: Universidad Nacional del Sur

Language: English

Topic: Estrogen and related hormone effects

Subfield: Endocrinology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: bronze

Funders: Consejo Nacional de Investigaciones Científicas y Técnicas, Agencia Nacional de Promoción Científica y Tecnológica