TY - JOUR
T1 - Terminal minihelix, a novel RNA motif that directs polymerase III transcripts to the cell cytoplasm
T2 - Terminal minihelix and RNA export
AU - Gwizdek, Carole
AU - Bertrand, Edouard
AU - Dargemont, Catherine
AU - Lefebvre, Jean Claude
AU - Blanchard, Jean Marie
AU - Singer, Robert H.
AU - Doglio, Alain
PY - 2001/7/13
Y1 - 2001/7/13
N2 - Determining the cis-acting elements controlling nuclear export of RNA is critical, because they specify which RNA will be selected for transport. We have characterized the nuclear export motif of the adenoviral VA1 RNA, a small cytoplasmic RNA transcribed by RNA polymerase III. Using a large panel of VA1 mutants in both transfected COS cells and injected Xenopus oocytes, we showed that the terminal stem of VA1 is necessary and sufficient for its export. Surprisingly, we found that the nucleotide sequence within the terminal stem is not important. Rather, the salient features of this motif are its length and its relative position within the RNA. Such stems thus define a novel and degenerate cytoplasmic localization motif that we termed the minihelix. This motif is found in a variety of polymerase III transcripts, and cross-competition analysis in Xenopus oocytes revealed that export of one such RNA, like hY1 RNA, is specifically competed by VA1 or artificial minihelix. Taken together these results show that the minihelix defines a new cis-acting export element and that this motif could be exported via a novel and specific nuclear export pathway.
AB - Determining the cis-acting elements controlling nuclear export of RNA is critical, because they specify which RNA will be selected for transport. We have characterized the nuclear export motif of the adenoviral VA1 RNA, a small cytoplasmic RNA transcribed by RNA polymerase III. Using a large panel of VA1 mutants in both transfected COS cells and injected Xenopus oocytes, we showed that the terminal stem of VA1 is necessary and sufficient for its export. Surprisingly, we found that the nucleotide sequence within the terminal stem is not important. Rather, the salient features of this motif are its length and its relative position within the RNA. Such stems thus define a novel and degenerate cytoplasmic localization motif that we termed the minihelix. This motif is found in a variety of polymerase III transcripts, and cross-competition analysis in Xenopus oocytes revealed that export of one such RNA, like hY1 RNA, is specifically competed by VA1 or artificial minihelix. Taken together these results show that the minihelix defines a new cis-acting export element and that this motif could be exported via a novel and specific nuclear export pathway.
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U2 - 10.1074/jbc.M100493200
DO - 10.1074/jbc.M100493200
M3 - Article
C2 - 11342536
AN - SCOPUS:0035854822
SN - 0021-9258
VL - 276
SP - 25910
EP - 25918
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 28
ER -