Identification of actin as an estradiol 17-beta-stimulated protein in the human placenta.
Addition of estradiol 17-beta to first trimester human placental minces resulted in an increased synthesis of a protein of apparent molecular weight 45 kDa. The specific involvement of estrogen in the stimulation of this protein was established by demonstrating a reduction in the level of this protein by the addition of CGS 16949 A, an inhibitor of aromatase, a key enzyme in the biosynthesis of estradiol 17-beta and ICI 182,780, an estrogen receptor antagonist. The protein was purified to homogeneity and N-terminal sequencing of two of the internal peptides obtained by enzymatic digestion of the protein, as well as the absence of a free N-terminal indicated that it could be actin. This was confirmed by Western blotting using commercially available actin antiserum. The role of estradiol 17-beta in the stimulation of actin synthesis in human placenta was also established by monitoring the quantitative inhibition of DNase I by actin.
Sudha
S
S
Department of Biochemistry, Indian Institute of Science, Bangalore, India.
Kumari
U
U
Rao
V S
VS
Rao
A J
AJ
D000199:Actins / Q000096:biosynthesis / Q000187:drug effects* / Q000302:isolation & purification*; D002824:Chorionic Villi / Q000187:drug effects / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000037:antagonists & inhibitors; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D017316:Fadrozole / Q000494:pharmacology; D005260:Female; D000077267:Fulvestrant; D006801:Humans; D008970:Molecular Weight; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000096:biosynthesis / Q000187:drug effects* / Q000302:isolation & purification*
D000199:Actins; D004965:Estrogen Antagonists; D011257:Pregnancy Proteins; D000077267:Fulvestrant; D004958:Estradiol; D003850:Deoxyribonuclease I; D017316:Fadrozole