The 3′-untranslated region of c-myc mRNA contains a perinuclear localisation signal which is sufficient to target beta-globin coding sequences. The link between perinuclear RNA localisation and translation has been investigated using cells transfected with chimeric gene constructs in which globin reporter sequences were linked to the c-myc 3′-untranslated region and the iron-responsive element from ferritin mRNA. Iron supplementation of the medium promoted translation of the chimeric mRNA as assessed by its presence in polysomes; in situ hybridisation showed that the mRNA was localised around the nucleus. Treatment with the iron chelator desferrioxamine for 16 h prevented both translation and mRNA localisation. In controls where the expressed mRNA lacked the iron-responsive element desferrioxamine had no effect upon localisation. In contrast, arrest of on-going global translation by puromycin treatment had no effect on mRNA localisation. The data suggest that if initiation of translation of a mRNA containing the c-myc localisation signal is prevented in some way then localisation does not occur, whereas once the mRNA has been localised further translation is not required to maintain mRNA localisation.
Localisation of a reporter transcript by the c-myc 3 ‘-UTR is linked to translation
Dalgleish, G. D.; Veyrune, J. L.; Accornero, N.; Blanchard, J. M.; Hesketh, J. E.
Nucleic Acids Research
1999-11-15 / vol 27 / pages 4363-4368
protein; intracellular-localization; elements; region; sequences; transport; actin messenger-rna; cytoplasm; cytoskeletal-bound polysomes; iron