Guttridge K L, Smith L D
Developmental Biology Center, University of California-Irvine, USA.
Zygote. 1995 May;3(2):111-22. doi: 10.1017/s0967199400002483.
Interspersed RNA makes up two-thirds of cytoplasmic polyadenylated RNA in Xenopus and sea urchin eggs. Although it has no known function, previous work has suggested that at least one family of interspersed RNA, XR, binds Xenopus oocyte proteins, and can influence the rate of translation. We have used two Xenopus repeat families, Ocr and XR, to explore their protein binding abilities. Ocr RNA binds the same pattern of highly abundant oocyte proteins that XR RNA binds, which are believed to be messenger ribonucleoprotein (mRNP) particle proteins. In addition, we show that Ocr RNA binds the Oct-60 protein, a member of the POU-domain family of transcription factors found in Xenopus oocytes. Using a 32 base pair sequence from the XR repeat in a DNA affinity column two proteins were isolated, 66 kDa and 92 kDa, that together form a complex with XR DNA. One of these proteins (92 kDa) also binds XR RNA. We suggest that the role of at least a subset of interspersed RNAs in development may be to bind, and sequester in the cytoplasm, DNA-binding proteins until the end of oogenesis.
散布RNA占非洲爪蟾和海胆卵细胞质多聚腺苷酸化RNA的三分之二。尽管其功能未知，但先前的研究表明，至少有一类散布RNA，即XR，能结合非洲爪蟾卵母细胞蛋白，并可影响翻译速率。我们利用非洲爪蟾的两个重复序列家族Ocr和XR来探究它们的蛋白结合能力。Ocr RNA结合的高丰度卵母细胞蛋白模式与XR RNA相同，这些蛋白被认为是信使核糖核蛋白（mRNP）颗粒蛋白。此外，我们发现Ocr RNA能结合Oct-60蛋白，它是在非洲爪蟾卵母细胞中发现的POU结构域转录因子家族的成员。利用来自XR重复序列的32个碱基对序列构建DNA亲和柱，分离出了两种蛋白，分子量分别为66 kDa和92 kDa，它们与XR DNA一起形成复合物。其中一种蛋白（92 kDa）也能结合XR RNA。我们认为，至少一部分散布RNA在发育过程中的作用可能是结合DNA结合蛋白并将其隔离在细胞质中，直到卵子发生结束。
