A Nervous System, High Expression Protein Bex1 And Its Interacting Protein Lmo2 Function In Transcriptional Regulation

The regulation of gene expression plays a key role in the process of development, among which, transcription regulation is the central event. Transcription regulation itself is a very complicated process, transcription regulator somehow is the most important molecules. The whole process requires both the interaction between transcription factors and DNA elements, and the interactions between transcription regulators. In recent years, the functions of LIM family proteins, especially in development, have drawn more and more attention. These protein family members which share a tandem double Zinc finger structure, obtained its name from the three first-identified members — Lin11, IsI1, and Mec3. It has been shown that LIM domain which contains two Zinc fingers can mediate protein-protein interaction but not DNA-protein interaction,LIM proteins can be classified LIM-hd, LIM-kinase and others according to other additional domains such as homeodomain , kinase domain. LIM proteins without other domains are called LMO (LIM-only proteins). They also can be classified as nuclear LOMs and cytoplasmic LOMs. LMO2 is one of nuclear LMOs.LMO2 was screened out in Yeast Two-Hybridization Assay using a bait protein BEX1 (brain expressed, X-chromosome linked protein 1), its function is poorly understood except for its involvement in X-inactivation. BEX1 is a small protein (125aa), with a leucine - rich NES located in the c-terminus.It has been shown that LMO2 is located specifically in hippocampus in the central nervous system (CNS). In situ hybridization showed that bex1 is also highly expressed in hippocampus.Northern blots analysis showeded that the expression patterns of Bexl and Lmo2 overlapped in mouse brain development. Both of them highly expressed in embryo, while descended sharply after birth, which suggested that these two genes might function in a...