@article { ISI:000343847000023,
	title = {Role of G-quadruplex located at 5 end of mRNAs},
	journal = {Biochimica Et Biophysica Acta-General Subjects},
	volume = {1840},
	number = {12},
	year = {2014},
	month = {DEC},
	pages = {3503-3510},
	publisher = {ELSEVIER SCIENCE BV},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>Background: Secondary structures in 5{\textquoteright} UTR of mRNAs play a critical role in regulating protein synthesis. Though studies have indicated the role of secondary structure G-quadruplex in translational regulation, position-specific effect of G-quadruplex in naturally occurring mRNAs is still not understood. As a pre-initiation complex recognises 5{\textquoteright} cap of the mRNA and scans along the untranslated region (UTR) before initiating translation, the presence of G-quadruplex in 5{\textquoteright} region may have a significant contribution in regulating translation. Here, we investigate the role of G-quadruplex located at the 5{\textquoteright} end of an mRNA. Methods: Biophysical characterisation of putative G-quadruplexes was performed using UV and CD spectroscopy. Functional implication of G-quadruplex in the context of their location was assessed in cellulo using gRT-PCR and dual luciferase assay system. Results: PG4 sequences in 5{\textquoteright} UTR of AICT interacting protein (AKTIP), cathepsin B (CTSB) and forkhead box E3 (FOXE3) mRNAs form G-quadruplex whereas it is unable to form G-quadruplex in apolipoprotein A-I binding protein (APOA1BP). Our results demonstrated diverse roles of G-quadruplex located at 5{\textquoteright} end of mRNAs. Though G-quadruplex in AKTIP and CTSB mRNA act as inhibitory modules, it activates translation in FOXE3 mRNA. Conclusions: Our works suggests that G-quadruplex present at the 5{\textquoteright} terminal of an mRNA behaves differently in a different gene context. It can activate or inhibit gene expression. General significance: This study demonstrated that it is difficult to predict the role of G-quadruplex on the basis of its position in 5{\textquoteright} UTR. The neighbouring nucleotide sequence, the intracellular milieu and the interacting partners might render diverse functions to this secondary structure. (C) 2014 Elsevier B.V. All rights reserved.</p>},
	keywords = {AKTIP, APOA1BP, CTSB, FOXE3, G-quadruplex, UTR},
	issn = {0304-4165},
	doi = {10.1016/j.bbagen.2014.08.017},
	author = {Agarwala, Prachi and Pandey, Satyaprakash and Maiti, Souvik}
}
