5"-3"Exoribonuclease 1 (XRN1)

XRN1 is an exoribonuclease enzyme. This enzyme is involves in 5’ to 3’ RNA degradation.The deduced 1,694-amino acid protein has a calculated molecular mass of 190 kD. It shares 92% homology with mouse Sep1, which the authors called Dhm1, over the N-terminal and central portions of the molecule, but only 74% homology at the C terminus. Northern blot analysis detected a predominant 10-kb transcript in all cells and organs tested except lung, liver, and kidney. Minor bands of about 5.5 kb were detected in testis and placenta. Epitope-tagged SEP1 was recovered in the cytoplasmic fraction of transfected 293 cells and showed an apparent molecular mass of about 208 kD. Fluorescence-tagged SEP1 localized to the cytoplasm, particularly the nuclear periphery, of transfected HeLa cells.