Jornal de Medicina e Terapia Molecular


Position dependence of an enhancer activity of the human beta-globin intron-ii, within a heterologous gene.

Alireza Zomorodipour, Elham Moein Jahromi, Fariba Ataei, Sepideh Valimehr

Function of intron II of the human beta globin on the human factor IX (hFIX) expression, with respect to its position within the coding region, was investigated. With this aim two hFIX expressing plasmids, in which the intron was inserted in either second or 3'-terminal intronic positions of the cDNA, in parallel with an intron-less clone, were used for the hFIX expression analysis in two mammalian cell lines, in transient states. Protein assays demonstrated the highest hFIX expression level for the construct with intron in the second position. This was also evidenced by a 3-fold increase in the hFIX transcription, relative to the variant with intron in the terminal position. The recombinant hFIX expressed by the three minigenes were biologically active, as it was demonstrated by clotting test. Results presented in this study, support the position dependence of an intron regulatory function, in an exogenous state, by effecting at either transcriptional or/and posttranscriptional level.