TY - JOUR
T1 - Mitochondrial localization of estrogen receptor β
AU - Yang, Shao Hua
AU - Liu, Ran
AU - Perez, Evelyn J.
AU - Wen, Yi
AU - Stevens, Stanley M.
AU - Valencia, Thomas
AU - Brun-Zinkernagel, Anne Marie
AU - Prokai, Laszlo
AU - Will, Yvonne
AU - Dykens, James
AU - Koulen, Peter
AU - Simpkins, James W.
PY - 2004/3/23
Y1 - 2004/3/23
N2 - Estrogen receptors (ERs) are believed to be ligand-activated transcription factors belonging to the nuclear receptor superfamily, which on ligand binding translocate into the nucleus and activate gene transcription. To date, two ERs have been identified: ERα and ERβ. ERα plays major role in the estrogen-mediated genomic actions in both reproductive and nonreproductive tissue, whereas the function of ERβ is still unclear. In this study, we used immunocytochemistry, immunoblotting, and proteomics to demonstrate that ERβ localizes to the mitochondria. In immunocytochemistry studies, ERβ was detected with two ERβ antibodies and found to colocalize almost exclusively with a mitochondrial marker in rat primary neuron, primary cardiomyocyte, and a murine hippocampal cell line. The colocalization of ERβ and mitochondrial markers was identified by both fluorescence and confocal microscopy. No translocation of ERβ into the nucleus on 17β-estradiol treatment was seen by using immunocytochemistry. Immunoblotting of purified human heart mitochondria showed an intense signal of ERβ, whereas no signals for nuclear and other organelle markers were found. Finally, purified human heart mitochondrial proteins were separated by SDS/PAGE. The 50,000-65,000 Mr band was digested with trypsin and subjected to matrix-assisted laser desorption/ionization mass spectrometric analysis, which revealed seven tryptic fragments that matched with those of ERβ. In summary, this study demonstrated that ERβ is localized to mitochondria, suggesting a role for mitochondrial ERβ in estrogen effects on this important organelle.
AB - Estrogen receptors (ERs) are believed to be ligand-activated transcription factors belonging to the nuclear receptor superfamily, which on ligand binding translocate into the nucleus and activate gene transcription. To date, two ERs have been identified: ERα and ERβ. ERα plays major role in the estrogen-mediated genomic actions in both reproductive and nonreproductive tissue, whereas the function of ERβ is still unclear. In this study, we used immunocytochemistry, immunoblotting, and proteomics to demonstrate that ERβ localizes to the mitochondria. In immunocytochemistry studies, ERβ was detected with two ERβ antibodies and found to colocalize almost exclusively with a mitochondrial marker in rat primary neuron, primary cardiomyocyte, and a murine hippocampal cell line. The colocalization of ERβ and mitochondrial markers was identified by both fluorescence and confocal microscopy. No translocation of ERβ into the nucleus on 17β-estradiol treatment was seen by using immunocytochemistry. Immunoblotting of purified human heart mitochondria showed an intense signal of ERβ, whereas no signals for nuclear and other organelle markers were found. Finally, purified human heart mitochondrial proteins were separated by SDS/PAGE. The 50,000-65,000 Mr band was digested with trypsin and subjected to matrix-assisted laser desorption/ionization mass spectrometric analysis, which revealed seven tryptic fragments that matched with those of ERβ. In summary, this study demonstrated that ERβ is localized to mitochondria, suggesting a role for mitochondrial ERβ in estrogen effects on this important organelle.
KW - Mitochondria
KW - Nuclear receptor
UR - http://www.scopus.com/inward/record.url?scp=12144289454&partnerID=8YFLogxK
U2 - 10.1073/pnas.0306948101
DO - 10.1073/pnas.0306948101
M3 - Article
C2 - 15024130
AN - SCOPUS:12144289454
SN - 0027-8424
VL - 101
SP - 4130
EP - 4135
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 12
ER -