title: The Role of Structural Elements of the 5'-Terminal Region of p53 mRNA in Translation under Stress Conditions Assayed by the Antisense Oligonucleotide Approach.
abstract: The p53 protein is one of the major factors responsible for cell cycle regulation and stress response. In the 5'-terminal region of p53 mRNA, an IRES element has been found which takes part in the translational regulation of p53 expression. Two characteristic hairpin motifs are present in this mRNA region: G56-C169, with the first AUG codon, and U180-A218, which interacts with the Hdm2 protein (human homolog of mouse double minute 2 protein). 2'-OMe modified antisense oligomers hybridizing to the 5'-terminal region of p53 mRNA were applied to assess the role of these structural elements in translation initiation under conditions of cellular stress. Structural changes in the RNA target occurring upon oligomers' binding were monitored by the Pb2+-induced cleavage method. The impact of antisense oligomers on the synthesis of two proteins, the full-length p53 and its isoform Δ40p53, was analysed in HT-29, MCF-7 and HepG2 cells, under normal conditions and under stress, as well as in vitro conditions. The results revealed that the hairpin U180-A218 and adjacent single-stranded region A219-A228 were predominantly responsible for high efficacy of IRES-mediated translation in the presence of stress factors. These motifs play a role of cis-acting elements which are able to modulate IRES activity, likely via interactions with protein factors.
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Swiatkowska
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
authors.forename: Paulina
authors.initials: P
authors.lastname: Zydowicz
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Gorska
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
authors.forename: Julia
authors.initials: J
authors.lastname: Suchacka
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
authors.forename: Mariola
authors.initials: M
authors.lastname: Dutkiewicz
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Ciesiołka
mesh_terms: D020121:5' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D018387:Codon, Initiator; D006801:Humans; D055029:Inverted Repeat Sequences; D009153:Mutagens / Q000494:pharmacology; D009690:Nucleic Acid Conformation; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000235:genetics*; D018384:Oxidative Stress / Q000235:genetics; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism; D013312:Stress, Physiological; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D020121:5' Untranslated Regions; D018387:Codon, Initiator; D009153:Mutagens; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53