REXO2 Is an Oligoribonuclease Active in Human Mitochondria

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Francesco Bruni (Author) Other; Pasqua Gramegna (Author) Other; Jorge M A Oliveira (Author) FFUP; Robert N Lightowlers (Author) Other; Zofia M A Chrzanowska Lightowlers (Author) Other

Journal

Title: PLoS ONE

Vol. 8 No. 1

Final page: e64670

ISSN: 1932-6203

Publisher: Public Library of Science

Indexing

ISI Web of Knowledge - 22 Citations

Scopus - 31 Citations

Other information

Authenticus ID: P-005-0MJ

DOI: 10.1371/journal.pone.0064670

Abstract (EN): The Escherichia coli oligoribonuclease, ORN, has a 3' to 5' exonuclease activity specific for small oligomers that is essential for cell viability. The human homologue, REXO2, has hitherto been incompletely characterized, with only its in vitro ability to degrade small single-stranded RNA and DNA fragments documented. Here we show that the human enzyme has clear dual cellular localization being present both in cytosolic and mitochondrial fractions. Interestingly, the mitochondrial form localizes to both the intermembrane space and the matrix. Depletion of REXO2 by RNA interference causes a strong morphological phenotype in human cells, which show a disorganized network of punctate and granular mitochondria. Lack of REXO2 protein also causes a substantial decrease of mitochondrial nucleic acid content and impaired de novo mitochondrial protein synthesis. Our data constitute the first in vivo evidence for an oligoribonuclease activity in human mitochondria.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11