Masking of mRNA by Y‐box proteins

The Y-box proteins are defined by their ability to bind to Y-box promoter elements and to help regulate transcription of a wide variety of genes. 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 vitro and in vivo, has been shown to effect their translational repression ("masking"). Here we discuss the ability of Y box proteins to recognize different nucleic acid structures and to become involved in regulation of both transcription and translation.