ABSTRACT
<p><b>OBJECTIVE</b>To identify the interaction partners of a new splicing product of LMO2 gene (LMO2-C), and study its function in K562 cells.</p><p><b>METHODS</b>Maltose binding protein (MBP) pull down and mammalian two-hybrid assay (MTHA) were used to identify the interaction partners of LMO2-C in K562 cells. Semiquantitative RT-PCR was used to detect the expression of hematopoietic specific gene glycoprotein (GPA) in K562 cells.</p><p><b>RESULTS</b>MBP-LMO2-C fusion protein was expressed and purified in soluble form successfully. Endogenous GATA1 and LDB1 proteins were confirmed to bind to LMO2-C by MBP pull down analysis. The MTHA also showed that LMO2-C had comparable binding affinities to LDB1 with LMO2-L, and over expression of LMO2-C prevented LMO2-L from binding to LDB1, the inhibition rate being (81.13 +/- 0.68)%. RT-PCR results showed that the expression level of GPA was reduced [(51.00 +/- 1.58)%] in K562 cells while LMO2-C overexpressed.</p><p><b>CONCLUSION</b>LMO2-C can bind endogenous GATA1 and LDB1 protein in K562 cells and down regulates the expression of GPA.</p>