Alternative splicing modulation mediated by G-quadruplex structures in MALAT1 lncRNA

ABSTRACT: MALAT1, an abundant lncRNA specifically localized to nuclear speckles, regulates alternative-splicing (AS). The molecular basis of its role in AS remains poorly understood. Here, we report three conserved, thermodynamically stable, parallel RNA-G-quadruplexes (rG4s) present in the 3’ region of MALAT1 which regulates this function. Using rG4 domain specific RNA-pull-down followed by mass-spectrometry, RNA-immuno-precipitation and imaging, we demonstrate the rG4 dependent localization of Nucleolin (NCL) and Nucleophosmin (NPM) to nuclear speckles. Specific G-to-A mutations that abolish rG4 structures, results in the localization loss of both the proteins from speckles. Functionally, disruption of rG4 in MALAT1 phenocopies NCL knockdown resulting in altered pre-mRNA splicing of endogenous genes. These results reveal a central role of rG4s within the 3’ region of MALAT1 orchestrating AS.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell, Cell Culture

DISEASE(S): Cervix Carcinoma

SUBMITTER: Arpita Ghosh  

LAB HEAD: Souvik Maiti

PROVIDER: PXD026386 | Pride | 2022-02-17

REPOSITORIES: Pride