The Rev protein is able to transport to the cytoplasm small nucleolar RNAscontaining a Rev binding element

Small nucleolar RNAs (snoRNAs) were utilized to express Rev-binding sequenc es inside the nucleolus and to test whether they are substrates for Rev bin ding and transport, We show that U16 snoRNA containing the minimal binding site for Rev stably accumulates inside the nucleolus maintaining the intera ction with the basic C/D snoRNA-specific factors. Upon Rev expression, the chimeric RNA is exported to the cytoplasm, where it remains bound to Rev in a particle devoid of snoRNP-specific factors, These data indicate that Rev can elicit the functions of RNA binding and transport inside the nucleolus .