Berger L C, Bag J, Sells B H
Department of Molecular Biology and Genetics, College of Biological Sciences, University of Guelph, Canada.
Eur J Biochem. 1992 Mar 1;204(2):733-43. doi: 10.1111/j.1432-1033.1992.tb16688.x.
Synthesis of poly(A)-binding protein is regulated at the translational level. We have investigated the binding of proteins to this mRNA on the premise that the protein(s) of the mRNP complex may be involved in regulating the expression of the mRNA. We found the first 243 nucleotides of the 5' untranslated region to contain sequences essential for RNP formation. A large, single-stranded bulge structure encompassing stretches rich in adenine nucleotides and a potential stem-loop domain appear to be the primary sites for protein binding. Removal of the 243-nucleotide segment results in a drastic reduction in protein binding and a concomitant increase in translational efficiency in vitro. We suggest that proteins binding to this region, including poly(A)-binding protein itself, may be essential for regulating translation of this mRNA.
聚腺苷酸结合蛋白的合成在翻译水平受到调控。我们基于mRNP复合物中的蛋白质可能参与调节该mRNA表达这一前提，研究了蛋白质与该mRNA的结合情况。我们发现5'非翻译区的前243个核苷酸包含形成RNP所必需的序列。一个包含富含腺嘌呤核苷酸区域的大的单链凸起结构以及一个潜在的茎环结构域似乎是蛋白质结合的主要位点。去除243个核苷酸片段会导致体外蛋白质结合急剧减少，同时翻译效率相应增加。我们认为，与该区域结合的蛋白质，包括聚腺苷酸结合蛋白本身，可能对调节该mRNA的翻译至关重要。
