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A novel mRNA‐decapping activity in HeLa cytoplasmic extracts is regulated by AU‐rich elements
Author(s) -
Gao Min,
Wilusz Carol J.,
Peltz Stuart W.,
Wilusz Jeffrey
Publication year - 2001
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 - 10.1093/emboj/20.5.1134
Subject(s) - medical school , library science , medicine , computer science , medical education
While decapping plays a major role in mRNA turnover in yeast, biochemical evidence for a similar activity in mammalian cells has been elusive. We have now identified a decapping activity in HeLa cytoplasmic extracts that releases 7me GDP from capped transcripts. Decapping is activated in extracts by the addition of 7me GpppG, which specifically sequesters cap‐binding proteins such as eIF4E and the deadenylase DAN/PARN. Similar to in vivo observations, the presence of a poly(A) tail represses decapping of RNAs in vitro in a poly(A)‐binding protein‐dependent fashion. AU‐rich elements (AREs), which act as regulators of mRNA stability in vivo , are potent stimulators of decapping in vitro . The stimulation of decapping by AREs requires sequence‐specific ARE‐binding proteins. These data suggest that cap recognition and decapping play key roles in mediating mRNA turnover in mammalian cells.