Exosome Component 5 (EXOSC5)

The deduced 235-amino acid RRP46 protein is 89% and approximately 28% identical to the mouse and yeast sequences, respectively. Western blot analysis and immunofluorescence microscopy showed expression of a 26-kD protein in the nucleus, with additional forms expressed in the cytoplasm and the highest concentration in nucleolus.

The CSL4 protein, but not mutant forms lacking N- or C-terminal residues, interacted directly with RRP42 and RRP46. The deletion mutants were also unable to interact with the exosome. RRP42 and RRP46 did not interact with each other.ARE recognition required certain ARE-binding proteins that could interact with the exosome and recruit it to unstable RNAs, thereby promoting their rapid degradation.