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: 3UTR_incomplete
The mRNA/+RNA description:
Putative in vivo CMV promoter-derived transcript produced from monocistronic plasmid pHIAP2(1073-1222)/CAT
which contains the part of human c-IAP1 5' UTR (nt from -150 to nt -1 of the original sequence) mRNA ahead of
chloramphenicol acetyltransferase reporter gene.
The sequence ends at its 3'-end right after the poly(A) signal from BGH mRNA and thus the 3'-UTR might be
slightly wrong.
The mRNA/+RNA sequence represented in the +DNA notation:
Credibility of mRNA sequence: reverse_engineered_sequence_and_should_match_experiment_maybe_except_3UTR
The name of the promoter used to express this mRNA: CMV
Aliases of the plasmid name:
Alias: HIAP2(1073-1222)CAT
Description of the plasmid (facultative for promoter-less plasmid records): Plasmid containing part of human c-IAP1 5' UTR (nt from -150 to nt -1 of the original sequence) ahead of
chloramphenicol acetyltransferase reporter gene.
The in vivo produced transcripts are heterogeneous (due to any of promoter?/splicing?/cleavage?/breakage?): no (not convincing)
The in vivo produced heterogeneous transcripts occur due to alternative splicing: not tested
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: unclear_result
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: not_tested
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 relative translation efficiency in % of this IRES: 1.000
Name of IRES used as the positive control: XIAP
Name of the plasmid used as the positive control. pXIAP(1-1076)/CAT
The relative translation efficiency in % of the positive control: 100.000
The size (length) of intercistronic region in the positive control: 0
The effect of 5'-cap analogs on translation: not tested
Rapamycin affects translation: not tested
Type of RNA subject to translation: endogenous_nuclear_RNA_Pol_II_transcript
Remarks:
The c-IAP1 5' UTR contains an upstream ORF (uORF) that prevents translation of the c-IAP1 ORF under normal
conditions (Warnakulasuriyarachchi et al., 2003) (this case of translation experiment).
Subsequent investigations revealed an IRES element at position -149 to position -1 in the c-IAP1 5' UTR that
mediates c-IAP1 translation following endoplasmic reticulum (ER) stress (treatment with etoposide or with
sodium arsenate (Van Eden et al., 2004) or treatment with thapsigargin (an inhibitor of ER calcium pump) or
tunicamycin (an inhibitor of protein glycosylation) (Warnakulasuriyarachchi et al., 2004)). Thus, expression
of c-IAP1 is regulated by a cap-independent translation initiation mechanism following cell stress. ER stress
causes cleavage of the eIF-4G family member p97/DAP5/NAT1 from its p97 form to a p86 form, and the p86 form
induces the activity of the c-IAP1 IRES resulting in an increase in c-IAP1 protein levels. However, direct
binding of the p86 form of p97/DAP5/NAT1 to c-IAP1 IRES RNA has not yet been demonstrated, and therefore p86
may exert its effect on c-IAP1 IRES activity either directly or via a downstream ITAF that interacts with the
c-IAP1 IRES.
Translational data are derived from Fig. 3A.