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The human core exosome interacts with differentially localized processive RNases: hDIS3 and hDIS3L
Author(s) -
Tomecki Rafal,
Kristiansen Maiken S,
LykkeAndersen Søren,
Chlebowski Aleksander,
Larsen Katja M,
Szczesny Roman J,
Drazkowska Karolina,
Pastula Agnieszka,
Andersen Jens S,
Stepien Piotr P,
Dziembowski Andrzej,
Jensen Torben Heick
Publication year - 2010
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2010.121
Subject(s) - exosome complex , biology , rnase p , exonuclease , rnase ph , rnase mrp , protein subunit , rna , microbiology and biotechnology , saccharomyces cerevisiae , exosome , helicase , biochemistry , rnase h , dna , yeast , microvesicles , polymerase , gene , microrna
The eukaryotic RNA exosome is a ribonucleolytic complex involved in RNA processing and turnover. It consists of a nine‐subunit catalytically inert core that serves a structural function and participates in substrate recognition. Best defined in Saccharomyces cerevisiae , enzymatic activity comes from the associated subunits Dis3p (Rrp44p) and Rrp6p. The former is a nuclear and cytoplasmic RNase II/R‐like enzyme, which possesses both processive exo‐ and endonuclease activities, whereas the latter is a distributive RNase D‐like nuclear exonuclease. Although the exosome core is highly conserved, identity and arrangements of its catalytic subunits in different vertebrates remain elusive. Here, we demonstrate the association of two different Dis3p homologs—hDIS3 and hDIS3L—with the human exosome core. Interestingly, these factors display markedly different intracellular localizations: hDIS3 is mainly nuclear, whereas hDIS3L is strictly cytoplasmic. This compartmental distribution reflects the substrate preferences of the complex in vivo . Both hDIS3 and hDIS3L are active exonucleases; however, only hDIS3 has retained endonucleolytic activity. Our data suggest that three different ribonucleases can serve as catalytic subunits for the exosome in human cells.