O'Brien C, Zabala G, Walbot V
Department of Biological Sciences, Stanford University, CA 94305.
Nucleic Acids Res. 1989 Jan 11;17(1):405-22. doi: 10.1093/nar/17.1.405.
Expression of a 130 kDa protein from open reading frame 1 of the integrated form of the R2 mitochondrial plasmid in normal mitochondria of B37 and other inbred lines is described. The protein appears identical to that synthesized by the closely related S2 episome found in cytoplasmic male sterile maize of the S type. Protein was detected using antisera raised against a beta-galactosidase:ORF1 fusion product containing the most antigenic region of the ORF1 product. Detection of this protein is in contrast to previous reports that mitochondria of normal, male-fertile lines either do not contain this protein, or that there are 11 in-frame stop codons in the reading frame. The integrated R2 of B37N was cloned and this region sequenced, confirming that a continuous open reading frame existed. These results are discussed in relation to the possible role of the S-type episomes in causing cytoplasmic male sterility.
本文描述了R2线粒体质粒整合形式的开放阅读框1中130 kDa蛋白在B37及其他近交系正常线粒体中的表达情况。该蛋白似乎与在S型细胞质雄性不育玉米中发现的密切相关的S2附加体所合成的蛋白相同。使用针对包含ORF1产物最具抗原性区域的β-半乳糖苷酶：ORF1融合产物产生的抗血清检测到了该蛋白。该蛋白的检测结果与之前的报道形成对比，之前的报道称正常可育雄性系的线粒体要么不含有这种蛋白，要么在阅读框中有11个框内终止密码子。克隆了B37N的整合型R2并对该区域进行了测序，证实存在一个连续的开放阅读框。结合S型附加体在导致细胞质雄性不育中可能发挥的作用对这些结果进行了讨论。
