A plethora of post-transcriptional mechanisms are involved in essentia
l steps in the pathway of genetic information expression in eukaryotes
. These processes are specified by cis-acting signals on RNAs and are
mediated by specific trans-acting factors, including RNA-binding prote
ins and small complementary RNAs. Recent information has begun to defi
ne the molecular mechanisms by which RNA-binding proteins recognize sp
ecific RNA sequences and influence the processing and function of RNA
molecules.