TY - JOUR
T1 - Proteasome-dependent degradation of the human estrogen receptor
AU - Nawaz, Zafar
AU - Lonard, David M.
AU - Dennis, Andrew P.
AU - Smith, Carolyn L.
AU - O'Malley, Bert W.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1999/3/2
Y1 - 1999/3/2
N2 - In eukaryotic cells, the ubiquitin-proteasome pathway is the major mechanism for the targeted degradation of proteins with short half-lives. The covalent attachment of ubiquitin to lysine residues of targeted proteins is a signal for the recognition and rapid degradation by the proteasome, a large multi-subunit protease. In this report, we demonstrate that the human estrogen receptor (ER) protein is rapidly degraded in mammalian cells in an estradiol-dependent manner. The treatment of mammalian cells with the proteasome inhibitor MG132 inhibits activity of the proteasome and blocks ER degradation, suggesting that ER protein is turned over through the ubiquitin- proteasome pathway. In addition, we show that in vitro ER degradation depends on ubiquitin-activating E1 enzyme (UBA) and ubiquitin-conjugating E2 enzymes (UBCs), and the proteasome inhibitors MG132 and lactacystin block ER protein degradation in vitro. Furthermore, the UBA/UBCs and proteasome inhibitors promote the accumulation of higher molecular weight forms of ER. The UBA and UBCs, which promote ER degradation in vitro, have no significant effect on human progesterone receptor and human thyroid hormone receptor β proteins.
AB - In eukaryotic cells, the ubiquitin-proteasome pathway is the major mechanism for the targeted degradation of proteins with short half-lives. The covalent attachment of ubiquitin to lysine residues of targeted proteins is a signal for the recognition and rapid degradation by the proteasome, a large multi-subunit protease. In this report, we demonstrate that the human estrogen receptor (ER) protein is rapidly degraded in mammalian cells in an estradiol-dependent manner. The treatment of mammalian cells with the proteasome inhibitor MG132 inhibits activity of the proteasome and blocks ER degradation, suggesting that ER protein is turned over through the ubiquitin- proteasome pathway. In addition, we show that in vitro ER degradation depends on ubiquitin-activating E1 enzyme (UBA) and ubiquitin-conjugating E2 enzymes (UBCs), and the proteasome inhibitors MG132 and lactacystin block ER protein degradation in vitro. Furthermore, the UBA/UBCs and proteasome inhibitors promote the accumulation of higher molecular weight forms of ER. The UBA and UBCs, which promote ER degradation in vitro, have no significant effect on human progesterone receptor and human thyroid hormone receptor β proteins.
UR - http://www.scopus.com/inward/record.url?scp=0033514930&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033514930&partnerID=8YFLogxK
U2 - 10.1073/pnas.96.5.1858
DO - 10.1073/pnas.96.5.1858
M3 - Article
C2 - 10051559
AN - SCOPUS:0033514930
VL - 96
SP - 1858
EP - 1862
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
SN - 0027-8424
IS - 5
ER -