PMID- 17470553
OWN - NLM
STAT- MEDLINE
DCOM- 20070809
LR  - 20181113
IS  - 0270-7306 (Print)
IS  - 1098-5549 (Electronic)
IS  - 0270-7306 (Linking)
VI  - 27
IP  - 13
DP  - 2007 Jul
TI  - Efficient translation initiation directed by the 900-nucleotide-long and GC-rich 
      5' untranslated region of the human retrotransposon LINE-1 mRNA is strictly cap 
      dependent rather than internal ribosome entry site mediated.
PG  - 4685-97
AB  - Retrotransposon L1 is a mobile genetic element of the LINE family that is 
      extremely widespread in the mammalian genome. It encodes a dicistronic mRNA, 
      which is exceptionally rare among eukaryotic cellular mRNAs. The extremely long 
      and GC-rich L1 5' untranslated region (5'UTR) directs synthesis of numerous 
      copies of RNA-binding protein ORF1p per mRNA. One could suggest that the 5'UTR of 
      L1 mRNA contained a powerful internal ribosome entry site (IRES) element. Using 
      transfection of cultured cells with the polyadenylated monocistronic (L1 
      5'UTR-Fluc) or bicistronic (Rluc-L1 5'UTR-Fluc) RNA constructs, capped or 
      uncapped, it has been firmly established that the 5'UTR of L1 does not contain an 
      IRES. Uncapping reduces the initiation activity of the L1 5'UTR to that of 
      background. Moreover, the translation is inhibited by upstream AUG codons in the 
      5'UTR. Nevertheless, this cap-dependent initiation activity of the L1 5'UTR was 
      unexpectedly high and resembles that of the beta-actin 5'UTR (84 nucleotides 
      long). Strikingly, the deletion of up to 80% of the nucleotide sequence of the L1 
      5'UTR, with most of its stem loops, does not significantly change its translation 
      initiation efficiency. These data can modify current ideas on mechanisms used by 
      40S ribosomal subunits to cope with complex 5'UTRs and call into question the 
      conception that every long GC-rich 5'UTR working with a high efficiency has to 
      contain an IRES. Our data also demonstrate that the ORF2 translation initiation 
      is not directed by internal initiation, either. It is very inefficient and 
      presumably based on a reinitiation event.
FAU - Dmitriev, Sergey E
AU  - Dmitriev SE
AD  - A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 
      Bldg. A, Moscow 119992, Russia.
FAU - Andreev, Dmitri E
AU  - Andreev DE
FAU - Terenin, Ilya M
AU  - Terenin IM
FAU - Olovnikov, Ivan A
AU  - Olovnikov IA
FAU - Prassolov, Vladimir S
AU  - Prassolov VS
FAU - Merrick, William C
AU  - Merrick WC
FAU - Shatsky, Ivan N
AU  - Shatsky IN
LA  - eng
GR  - FIRCA PA-02-057/PHS HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20070430
PL  - United States
TA  - Mol Cell Biol
JT  - Molecular and cellular biology
JID - 8109087
RN  - 0 (5' Untranslated Regions)
RN  - 0 (Codon, Initiator)
RN  - 0 (RNA Caps)
RN  - 0 (RNA, Messenger)
RN  - 0 (Regulatory Sequences, Ribonucleic Acid)
RN  - 9007-49-2 (DNA)
SB  - IM
MH  - 5' Untranslated Regions/*genetics
MH  - *Base Pairing
MH  - Cell Line
MH  - Codon, Initiator/genetics
MH  - DNA
MH  - GC Rich Sequence/*genetics
MH  - HeLa Cells
MH  - Humans
MH  - Long Interspersed Nucleotide Elements/*genetics
MH  - Open Reading Frames/genetics
MH  - *Peptide Chain Initiation, Translational
MH  - RNA Caps/*genetics
MH  - RNA, Messenger/chemistry/genetics
MH  - Regulatory Sequences, Ribonucleic Acid/*genetics
MH  - Ribosomes/genetics
MH  - Transfection
PMC - PMC1951496
EDAT- 2007/05/02 09:00
MHDA- 2007/08/10 09:00
PMCR- 2007/11/01
CRDT- 2007/05/02 09:00
PHST- 2007/05/02 09:00 [pubmed]
PHST- 2007/08/10 09:00 [medline]
PHST- 2007/05/02 09:00 [entrez]
PHST- 2007/11/01 00:00 [pmc-release]
AID - MCB.02138-06 [pii]
AID - 2138-06 [pii]
AID - 10.1128/MCB.02138-06 [doi]
PST - ppublish
SO  - Mol Cell Biol. 2007 Jul;27(13):4685-97. doi: 10.1128/MCB.02138-06. Epub 2007 Apr 
      30.