What's new about CNBP? Divergent functions and activities for a conserved nucleic acid binding protein

Abstract

Background: Cellular nucleic acid binding protein (CNBP) is a conserved single-stranded nucleic acid binding protein present in most eukaryotes, but not in plants. Expansions in the CNBP gene cause myotonic dystrophy type 2. Initially reported as a transcriptional regulator, CNBP was then also identified acting as a translational regulator. Scope of review: The focus of this review was to link the CNBP structural features and newly reported biochemical activities with the recently described biological functions, in the context of its pathological significance. Major conclusions: Several post-translational modifications affect CNBP subcellular localization and activity. CNBP participates in the transcriptional and translational regulation of a wide range of genes by remodeling single-stranded nucleic acid secondary structures and/or by modulating the activity of trans-acting factors. CNBP is required for proper neural crest and heart development, and plays a role in cell proliferation control. Besides, CNBP has been linked with neurodegenerative, inflammatory, and congenital diseases, as well as with tumor processes. General significance: This review provides an insight into the growing functions of CNBP in cell biology. A unique and robust mechanistic or biochemical connection among these roles has yet not been elucidated. However, the ability of CNBP to dynamically integrate signaling pathways and to act as nucleic acid chaperone may explain most of the roles and functions identified so far.