Good P J, Chen Q, Warner S J, Herring D C
Department of Biochemistry and Molecular Biology and Feist-Weiller Cancer Center, Louisiana State University, Health Sciences Center, Shreveport, Lousiana 71130, USA.
J Biol Chem. 2000 Sep 15;275(37):28583-92. doi: 10.1074/jbc.M003083200.
The post-transcriptional regulation of gene expression by RNA-binding proteins is an important element in controlling both normal cell functions and animal development. The diverse roles are demonstrated by the Elav family of RNA-binding proteins, where various members have been shown to regulate several processes involving mRNA. We have identified another family of RNA-binding proteins distantly related to the Elav family but closely related to Bruno, a translational regulator in Drosophila melanogaster. In humans, six Bruno-like genes have been identified, whereas other species such as Drosophila, Xenopus laevis, and Caenorhabditis elegans have at least two members of this family, and related genes have also been detected in plants and ascidians. The human BRUNOL2 and BRUNOL3 are 92% identical in the RNA-binding domains, although the BRUNOL2 gene is expressed ubiquitously whereas BRUNOL3 is expressed predominantly in the heart, muscle, and nervous system. Both of these proteins bind the same target RNA, the Bruno response element. The RNA-binding domain that recognizes the Bruno response element is composed of two consecutive RNA recognition motifs at the amino terminus of vertebrate Bruno protein. The possible involvement of the Bruno family of proteins in the CUG repeat expansion disease myotonic dystrophy is discussed.
RNA结合蛋白对基因表达的转录后调控是控制正常细胞功能和动物发育的重要因素。RNA结合蛋白的Elav家族展示了其多样的作用，其中多个成员已被证明可调控涉及mRNA的多个过程。我们鉴定出了另一个与Elav家族远缘相关但与果蝇中的翻译调节因子Bruno密切相关的RNA结合蛋白家族。在人类中，已鉴定出六个类Bruno基因，而果蝇、非洲爪蟾和秀丽隐杆线虫等其他物种至少有该家族的两个成员，并且在植物和海鞘中也检测到了相关基因。人类的BRUNOL2和BRUNOL3在RNA结合结构域中有92%的同一性，尽管BRUNOL2基因在全身表达，而BRUNOL3主要在心脏、肌肉和神经系统中表达。这两种蛋白质都结合相同的靶RNA，即Bruno反应元件。识别Bruno反应元件的RNA结合结构域由脊椎动物Bruno蛋白氨基末端的两个连续RNA识别基序组成。本文还讨论了Bruno蛋白家族可能参与CUG重复扩增疾病强直性肌营养不良的情况。
