Gaskins C J, Fiser-Littell R M, Duke A L, Hanas J S
Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City 73190.
Nucleic Acids Res. 1989 Jan 25;17(2):781-94. doi: 10.1093/nar/17.2.781.
Species variation in transcription factor IIIA (TFIIIA) was examined by comparing the abilities of TFIIIAs isolated from different Xenopus and Rana species to 1) bind rabbit anti-Xenopus laevis TFIIIA IgG, 2) specifically interact with the Xenopus borealis somatic 5S RNA gene, and 3) promote transcription of the Xenopus borealis 5S RNA gene in vitro. In immunoblot assays, Rana catesbeiana or Rana pipiens TFIIIA did not react readily with rabbit anti-Xenopus laevis TFIIIA IgG (assayed with anti-rabbit F(ab')2 fragment conjugated with alkaline phosphatase) whereas Xenopus borealis TFIIIA exhibited similar reactivity with this IgG as Xenopus laevis TFIIIA. When compared to Xenopus TFIIIAs, Rana TFIIIAs exhibited similar interactions with the 3' portion of the intragenic control region of the Xenopus 5S RNA gene (to residue +78 on the coding strand and up to and including +74 on the non-coding strand, nucleotides protected from DNase I digestion by the N-terminal half of Xenopus TFIIIA) and incomplete interactions with the remaining 5' portion of the control region (nucleotides protected from DNase I digestion by the C-terminal half of Xenopus TFIIIA). In a Xenopus laevis unfertilized egg extract, Rana catesbeiana and Rana pipiens TFIIIAs promoted transcription of the Xenopus borealis somatic 5S RNA gene less efficiently than Xenopus laevis and Xenopus borealis TFIIIAs.
通过比较从不同非洲爪蟾和林蛙物种中分离出的转录因子IIIA（TFIIIA）的能力，研究了物种间的差异，这些能力包括：1）结合兔抗非洲爪蟾TFIIIA IgG；2）与北美爪蟾体细胞5S RNA基因特异性相互作用；3）在体外促进北美爪蟾5S RNA基因的转录。在免疫印迹分析中，牛蛙或豹蛙的TFIIIA不易与兔抗非洲爪蟾TFIIIA IgG发生反应（用与碱性磷酸酶偶联的抗兔F(ab')2片段检测），而北美爪蟾TFIIIA与这种IgG的反应性与非洲爪蟾TFIIIA相似。与非洲爪蟾TFIIIA相比，林蛙TFIIIA与非洲爪蟾5S RNA基因基因内控制区的3'部分（编码链上至+78位，非编码链上至并包括+74位，这些核苷酸被非洲爪蟾TFIIIA N端一半保护不被DNase I消化）表现出相似的相互作用，而与控制区其余的5'部分（被非洲爪蟾TFIIIA C端一半保护不被DNase I消化的核苷酸）的相互作用不完全。在非洲爪蟾未受精卵提取物中，牛蛙和豹蛙的TFIIIA促进北美爪蟾体细胞5S RNA基因转录的效率低于非洲爪蟾和北美爪蟾的TFIIIA。
