AU-rich elements target small nuclear RNAs as well as mRNAs for rapid degradation

1. Xinhao Cynthia Fan,
2. Vic E. Myer1, and
3. Joan A. Steitz2

1. Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, Connecticut 06520 USA

Abstract

AU-rich elements (AREs, usually containing repeated copies of AUUUA), when present in the 3′-untranslated regions (UTRs) of many mammalian mRNAs, confer instability on their host RNA molecules. The viral small nuclear RNA (snRNA) Herpesvirus saimiri U RNA 1 (HSUR 1) also contains an AUUUA-rich sequence. Here, we report that this ARE induces rapid degradation of HSUR 1 itself and of other snRNAs including HSUR 2 and cellular U1. Mutational analyses of the viral ARE establish that sequence requirements for mRNA and snRNA decay are the same, suggesting a similar mechanism. Moreover, the in vivo degradation activity of mutant AREs correlates with their in vitro binding to the HuR protein, implicated previously as a component of the mRNA degradation machinery. Our results suggest that ARE-mediated instability can be uncoupled from both ongoing translation and deadenylation of the target RNA.

• ARE
• HSUR 1
• RNA degradation
• HuR
• Herpesvirus saimiri

Footnotes

• ↵1 Present address: Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142 USA.

• ↵2 Corresponding author.

• E-MAIL Joan.Steitz{at}Yale.edu; FAX (203) 624-8213.

• • Received June 5, 1997.
  • Accepted August 4, 1997.
• Cold Spring Harbor Laboratory Press