Nuclear RNA-binding Proteins

The control of gene expression involves several steps at which specific sequences in pre-mRNA transcripts, as well as those in small RNA molecules, are recognized by proteins. RNA-binding proteins can be expected to mediate interactions in a variety of cellular processes, including those occurring in the transcription complex, the spliceosome and ribosome. The members of one family of nuclear proteins that bind to RNA contain a specific RNA recognition motif (RRM). The RRM family of proteins functions at several levels in RNA processing and some family members are involved in tissue-specific and developmentally regulated gene expression. This chapter describes the proteins that contain this RRM and discusses the potential involvement of these proteins in the control of gene expression at the level of RNA processing. These proteins are modular in structure and often contain at least two types of interactive surfaces—one or more that interacts specifically with RNA and another that interacts with other molecules. Studies to date indicate that despite the strong homology among these proteins, they have unique properties of recognition that allow them to distinguish the RNAs of diverse structure.