tailieunhanh - Homo-binding character of LMO2 isoforms and their both synergic and antagonistic functions in regulating hematopoietic-related target genes

The human lmo2 gene plays important roles in hematopoiesis and is associated with acute T lymphocyte leukemia. The gene encodes two protein isoforms, a longer form LMO2-L and a shorter form LMO2-S. Both isoforms function as bridge molecules to assemble their partners together to regulate their target genes. A typical LMO2 binding site consists of two elements, a GATA site and an E-box, with an interval of 9~12 bp. Methods: In this study, the combination of MBP pulldown assay and mammalian two hybrid assay were. | Sun et al. Journal of Biomedical Science 2010 17 22 http content 17 1 22 I NSC The cost of publication in Journal of Biomedical Science is bourne by the National Science Council Taiwan. JOURNAL OF BIOMEDICAL SCIENCE RESEARCH Open Access Homo-binding character of LMO2 isoforms and their both synergic and antagonistic functions in regulating hematopoietic-related target genes Wei Sun Wen-Wen Shen Shuang Yang Fen Hu Yang Gao Yu-Huan Qiao and Tian-Hui Zhu Abstract Background The human lmo2 gene plays important roles in hematopoiesis and is associated with acute T lymphocyte leukemia. The gene encodes two protein isoforms a longer form LMO2-L and a shorter form LMO2-S. Both isoforms function as bridge molecules to assemble their partners together to regulate their target genes. A typical LMO2 binding site consists of two elements a GATA site and an E-box with an interval of 9 12 bp. Methods In this study the combination of MBP pulldown assay and mammalian two hybrid assay were used to confirm the homo-binding character of LMO2-L -S isoforms. Luciferase reporter assay and Real-time PCR assay were used to detect expression levels and relative promoter activities of LMO2-L -S isoforms. Co-transfection and Luciferase reporter assay were used to reveal the detailed regulatory pattern of LMO2-L -S isoforms on their targets. Results Herein we report the homo-interaction character of LMO2-L and LMO2-S and their major difference in manner of regulating their target genes. Our results showed that LMO2-L and LMO2-S could only bind to themselves but not each other. It was also demonstrated that LMO2-L could either positively or negatively regulate the transcription of its different target genes depending on the arrangement and strand location of the two elements GATA site and E-box LMO2-S however performed constitutively transcriptional inhibiting function on all target genes. Conclusion These results suggest that LMO2 isoforms have independent functions while .