IRESite record type: plasmid_with_promoter_and_putative_IRES_translationally_characterized
The shape of the nucleic acid molecule translated: linear
The quality of the mRNA/+RNA sequence: our_best_guess
The mRNA/+RNA description:
Putative in vivo transcript driven from CMV IE promoter and terminated after the SV40 late poly(A) signal
containing GLuc (Gaussia luciferase) and GFP cistrons separated by the putative XIAP IRES.
The mRNA/+RNA sequence represented in the +DNA notation:
Credibility of mRNA sequence: end-to-end_sequence_reverse_engineered_and_should_match_experiment
The name of the promoter used to express this mRNA: CMV_IE
The in vivo produced transcripts are heterogeneous (due to any of promoter?/splicing?/cleavage?/breakage?): yes
The in vivo produced heterogeneous transcripts occur due to alternative splicing: yes
A promoter reported in cDNA corresponding to IRES sequence: not tested
Summary of possible issues when IRES cDNA is experimentally transcribed in vivo:
Summary of experiments studying integrity of the in vivo transcripts in a particular host:
Integrity (uniformity) of mRNA tested using Northern-blot: not_tested
Integrity (uniformity) of mRNA tested using RNase protection: not_tested
Integrity (uniformity) of mRNA tested using 5'-RACE: not_tested
Integrity (uniformity) of mRNA tested using primer extension : not_tested
Integrity (uniformity) of mRNA tested using RT-PCR: heterogeneous_population_of_molecules_found
Integrity (uniformity) of mRNA tested using real-time quantitative polymerase chain reaction (rtqPCR): not_tested
Integrity (uniformity) of mRNA tested using RNAi: not_tested
Integrity (uniformity) of mRNA tested using S1 nuclease mapping: not_tested
Cryptic promoter presence was confirmed by expression from a promoter-less plasmid: not_tested
Cryptic promoter presence was confirmed in an experimental setup involving inducible promoter: not_tested
Integrity (uniformity) of mRNA molecules or possible promoter presence expressed in vivo was tested using another method, please specify in Remarks: not_tested
The description of the protein encoded in this ORF: green fluorescent protein
The translational frameshift (ribosome slippage) involved: 0
The ribosome read-through involved: no
The alternative forms of this protein occur by the alternative initiation of translation: not tested
The ORF absolute position (the base range includes START and STOP codons or their equivalents): 942-1661
Remarks:
In addition to the unspliced message 3 alternatively spliced products were reported in HeLa cells transiently
transfected by this plasmid. Although the authors intended to use a plasmid which would be depleted of
5'-splice donor sites (Supplementary Figure 6) still two 5'-splice donor sites remained in GLuc coding region
and spliced with eIF4GI insert. In case of this plasmid with XIAP insert the 5'-donor splice site was same
with one of the two found with eIF4GI insert. Please refer to the Supplementary Figure 7 in Baranick et al.
(2008).
The sequences around the 5'-splice donor were:
GAATGATGTGgtaatgtcga (in XIAP IRES itself)
GTTTAAACGCgtattagttt (located in MluI A^CGCgt site used for cloning of the cDNA immediately upstream of XIAP
IRES) ACCTTCGCAAgcaagatcca (in GLuc coding region, C-terminus)
The 3'-splice acceptor region was: atataatgttctctttttagAA
Comments from IRESite curator:
The first variant has shorter XIAP insert while both reporter ORFs are intact, having 138bp in the
intercistronic region (instead of 293 in the unspliced message).
The second splice variant lacks almost completely the XIAP insert while is still bicistronic, having 47bp in
the intercistronic region.
The third splice variant has GLuc ORF merged in-frame to the second cistron so a fusion protein could be
produced.