Sani B P, Donovan M K
Cancer Res. 1979 Jul;39(7 Pt 1):2492-6.
Retinoic acid-binding protein (RABP) has been detected in the nuclei of chick embryo skin and Lewis lung tumor. The nuclear binding component showed the same ligand specificity and sedimentation value as the cytosol RABP. Whereas pronase completely digested the nuclear binding component, DNase showed 40%, and RNase showed negligible digestive action. Retinoic acid binding to the nuclear RABP was completely inhibited by a mercurial, and the inhibition was reversed by dithiothreitol. The nonspecific uptake of retinoic acid by Lewis drug nuclei and chick embryo skin nuclei was inhibited up to 50% by cytosol RABP. The maximal inhibitory effect produced by cytosol RABP was after 45-min incubation. Incubation of Lewis lung tumor with [3H]retinoic acid resulted in the appearance of nuclear RABP: [3H]retinoic acid in the nuclei. The complex formed was weak, and most of the bound retinoic acid could be removed by dialysis.
维甲酸结合蛋白(RABP)已在鸡胚皮肤和刘易斯肺癌细胞核中被检测到。核结合成分显示出与胞质溶胶RABP相同的配体特异性和沉降值。而链霉蛋白酶可完全消化核结合成分,脱氧核糖核酸酶显示出40%的消化作用,核糖核酸酶显示出可忽略不计的消化作用。汞剂可完全抑制维甲酸与核RABP的结合,二硫苏糖醇可逆转这种抑制作用。胞质溶胶RABP可将刘易斯肺癌细胞核和鸡胚皮肤细胞核对维甲酸的非特异性摄取抑制达50%。胞质溶胶RABP产生的最大抑制作用出现在孵育45分钟后。用[3H]维甲酸孵育刘易斯肺癌可导致核RABP的出现:细胞核中出现[3H]维甲酸。形成的复合物较弱,大部分结合的维甲酸可通过透析去除。