Kulkarni A B, Gubits R M, Feigelson P
Proc Natl Acad Sci U S A. 1985 May;82(9):2579-82. doi: 10.1073/pnas.82.9.2579.
Hepatic alpha 2u-globulin protein and RNA levels are under developmental and complex multihormonal control. The present studies directly evaluate the degree to which this regulation is transcriptional. alpha 2u-Globulin transcription was determined by measuring nuclear runoff RNA in vitro, and tissue alpha 2u-globulin mRNA levels were measured by dot blot hybridization. These studies reveal that (i) in male rats the transcriptional rate of the alpha 2u-globulin genes increases during postnatal development; (ii) no alpha 2u-globulin transcription is detectable in hepatic nuclei derived from hypophysectomized rats; (iii) growth hormone and glucocorticoid are both absolutely required, and glucocorticoid can replace androgen for alpha 2u-globulin gene transcription in the livers of hypophysectomized male rats; and (iv) chronic treatment of mature male rats with estrogen results in a progressive decrease in the hepatic transcription of alpha 2u-globulin genes. In all instances changes in the transcriptional rate of alpha 2u-globulin genes paralleled the tissue level of alpha 2u-globulin RNA. Thus transcriptional control predominates in regulating hepatic alpha 2u-globulin RNA levels.
肝脏α2u-球蛋白的蛋白质和RNA水平受发育及多种复杂激素的调控。本研究直接评估了这种调控在转录水平上的程度。通过体外测量核延伸RNA来确定α2u-球蛋白的转录情况，通过斑点杂交法测量组织中α2u-球蛋白mRNA的水平。这些研究表明：（i）在雄性大鼠中，α2u-球蛋白基因的转录率在出生后发育过程中增加；（ii）在垂体切除大鼠的肝细胞核中未检测到α2u-球蛋白转录；（iii）生长激素和糖皮质激素都是绝对必需的，并且在垂体切除的雄性大鼠肝脏中，糖皮质激素可以替代雄激素用于α2u-球蛋白基因转录；（iv）用雌激素长期处理成熟雄性大鼠会导致α2u-球蛋白基因的肝脏转录逐渐减少。在所有情况下，α2u-球蛋白基因转录率的变化与α2u-球蛋白RNA的组织水平平行。因此，转录调控在调节肝脏α2u-球蛋白RNA水平中起主导作用。
