TY - JOUR
T1 - A middle-affinity estrogen-specific binding protein in livers of vitellogenic and nonvitellogenic Xenopus laevis
AU - Hayward, Marshall A.
AU - Shapiro, David J.
PY - 1981/12
Y1 - 1981/12
N2 - Administration of estradiol-17β to male Xenopus laevis evokes massive liver synthesis of the egg yolk precursor protein, vitellogenin, and its cognate mRNA. Since previous experiments had implicated only a nuclear estrogen receptor in vitellogenesis, we examined Xenopus liver cytosol for other estrogen-binding proteins. Cytoplasmic extracts from unstimulated Xenopus liver contain high levels (approximately 500,000 sites/cell) of an estrogen-specific binding protein. This protein exhibits a Kd of approximately 4 × 10-8M for estradiol-17β, binds estrogenic steroids only, and has a sedimentation coefficient in the range 2-3 S. It is not a classical estrogen receptor, as it does not translocate into the nucleus following estrogen administration. We discuss possible functions of this protein, which include a role in the ontogeny of the vitellogenic response, and in the cytoplasmic transport and storage of estrogen.
AB - Administration of estradiol-17β to male Xenopus laevis evokes massive liver synthesis of the egg yolk precursor protein, vitellogenin, and its cognate mRNA. Since previous experiments had implicated only a nuclear estrogen receptor in vitellogenesis, we examined Xenopus liver cytosol for other estrogen-binding proteins. Cytoplasmic extracts from unstimulated Xenopus liver contain high levels (approximately 500,000 sites/cell) of an estrogen-specific binding protein. This protein exhibits a Kd of approximately 4 × 10-8M for estradiol-17β, binds estrogenic steroids only, and has a sedimentation coefficient in the range 2-3 S. It is not a classical estrogen receptor, as it does not translocate into the nucleus following estrogen administration. We discuss possible functions of this protein, which include a role in the ontogeny of the vitellogenic response, and in the cytoplasmic transport and storage of estrogen.
UR - http://www.scopus.com/inward/record.url?scp=0019802011&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0019802011&partnerID=8YFLogxK
U2 - 10.1016/0012-1606(81)90177-9
DO - 10.1016/0012-1606(81)90177-9
M3 - Article
C2 - 7308579
AN - SCOPUS:0019802011
VL - 88
SP - 333
EP - 340
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 2
ER -