Kaulen H, Pognonec P, Gregor P D, Roeder R G
Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021-6399.
Mol Cell Biol. 1991 Jan;11(1):412-24. doi: 10.1128/mcb.11.1.412-424.1991.
The Xenopus laevis TFIIIA promoter contains a motif that has been implicated in promoter activation in late-stage oocytes and contains the sequence (-269) CACGTG (-264). A cDNA encoding a protein (B1) that binds to this element has been cloned from X. laevis and Xenopus borealis ovarian cDNA libraries. We show that this protein is a member of the helix-loop-helix family of regulatory proteins and contains 80% sequence identity with the human adenovirus major late transcription factor (MLTF or USF). A survey of B1 protein expression during oogenesis and embryogenesis revealed both oocyte-specific and somatic cell-specific B1 protein-DNA complexes. Immunological data, RNA blot analysis, and proteolytic clipping band shift assays indicated that these complexes most likely represent altered forms of a single B1 polypeptide. Implications for TFIIIA gene regulation during development are discussed.
非洲爪蟾的TFIIIA启动子含有一个基序，该基序与晚期卵母细胞中的启动子激活有关，并且包含序列（-269）CACGTG（-264）。已从非洲爪蟾和北方爪蟾的卵巢cDNA文库中克隆出一种编码与该元件结合的蛋白质（B1）的cDNA。我们表明，这种蛋白质是调节蛋白螺旋-环-螺旋家族的成员，与人类腺病毒主要晚期转录因子（MLTF或USF）具有80%的序列同一性。对卵母细胞发生和胚胎发生过程中B1蛋白表达的调查揭示了卵母细胞特异性和体细胞特异性的B1蛋白-DNA复合物。免疫学数据、RNA印迹分析和蛋白水解剪切带迁移分析表明，这些复合物很可能代表单一B1多肽的改变形式。文中讨论了其对发育过程中TFIIIA基因调控的意义。
