MASKING OF MESSENGER-RNA BY Y-BOX PROTEINS

The Y-box proteins are defined by their ability to bind to Y-box promo ter elements and to help regulate transcription of a wide variety of g enes. However, Y-box proteins are also identified as abundant proteins in the cytoplasm of germ cells, where they are found bound to stored mRNA molecules. Binding of Y-box proteins to mRNA sequences, both in v itro and in vivo, has been shown to effect their translational repress ion (''masking''). Here we discuss the ability of Y box proteins to re cognize different nucleic acid structures and to become involved in re gulation of both transcription and translation.