Brantley K M, Whelly S M
Department of Biochemistry, Texas Tech University, Lubbock 79430.
J Steroid Biochem. 1990 Mar;35(3-4):367-75. doi: 10.1016/0022-4731(90)90242-k.
Administration of estradiol (E2) to ovariectomized mature rats resulted in a time-dependent increased transcriptional activity of uterine nucleoli isolated from hormone-treated animals compared to uterine nucleoli isolated from control animals. Early (4 h) E2 stimulation of uterine nucleolar transcription, resulted from an increased rate of elongation of chain growth on preinitiated nucleolar RNA with no significant effect of E2 on the number of nucleolar RNA chains being synthesized. Longer (24 h) treatment of animals with hormone resulted in both significant increased numbers of uterine nucleolar RNA chains in the act of synthesis and increased rate of elongation of nucleolar RNA chain growth. Salt extraction (150 mM NaCl) of uterine nucleoli isolated from 4 h E2-treated animals decreased transcriptional activity to the level observed in nucleoli isolated from control animals. The loss in nucleolar transcriptional activity from salt extraction was due to decreased rate of elongation of nucleolar RNA synthesis with no significant effect on the number of RNA chains being synthesized. Salt extracts from nucleoli isolated from 4 h E2-treated animals, but not control animals, contained factor(s) capable of stimulating the rate of elongation of nucleoli isolated from control animals to elongation rates observed in unextracted nucleoli isolated from 4 h E2-treated animals. Synthesis and phosphorylation of a high molecular weight uterine nucleolar protein(s) was seen after 4 h of E2 treatment with the nucleolar phosphoprotein(s) salt extractable.
与从对照动物分离的子宫核仁相比，给去卵巢的成年大鼠施用雌二醇（E2）导致从激素处理动物分离的子宫核仁的转录活性随时间增加。E2对子宫核仁转录的早期（4小时）刺激，是由于起始前核仁RNA上链生长的延伸速率增加，而E2对正在合成的核仁RNA链的数量没有显著影响。用激素对动物进行较长时间（24小时）的处理，导致正在合成的子宫核仁RNA链数量显著增加，以及核仁RNA链生长的延伸速率增加。从4小时E2处理动物分离的子宫核仁进行盐提取（150 mM NaCl），使转录活性降低到从对照动物分离的核仁中观察到的水平。盐提取导致的核仁转录活性丧失是由于核仁RNA合成的延伸速率降低，而对正在合成的RNA链数量没有显著影响。从4小时E2处理动物分离的核仁的盐提取物，但不是对照动物的盐提取物，含有能够将从对照动物分离的核仁的延伸速率刺激到从4小时E2处理动物分离的未提取核仁中观察到的延伸速率的因子。E2处理4小时后，可见一种高分子量子宫核仁蛋白的合成和磷酸化，且该核仁磷蛋白可被盐提取。
