Conserved regions of the DMD 3′ UTR regulate translation and mRNA abundance in cultured myotubes

Abstract

Duchenne muscular dystrophy (DMD), a severe muscle-wasting disease, is caused by mutations in the DMD gene, which encodes for the protein dystrophin. Its regulation is of therapeutic interest as even small changes in expression of functional dystrophin can significantly impact the severity of DMD. While tissue-specific distribution and transcriptional regulation of several DMD mRNA isoforms has been well characterized, the post-transcriptional regulation of dystrophin synthesis is not well understood. Here, we utilize qRTPCR and a quantitative dual-luciferase reporter assay to examine the effects of isoform specific DMD 5’ UTRs and the highly conserved DMD 3’ UTR on mRNA abundance and translational control of gene expression in C2C12 cells. The 5’ UTRs were shown to initiate translation with low efficiency in both myoblasts and myotubes. Whereas, two large highly conserved elements in the 3’ UTR, which overlap the previously described Lemaire A and D regions, increase mRNA levels and enhance translation upon differentiation of myoblasts into myotubes. The results presented here implicate an important role for DMD UTRs in dystrophin expression and delineate the cis-acting elements required for the myotube-specific regulation of steady-state mRNA levels and translational enhancer activity found in the DMD 3’ UTR.

In vivo dynamics of skeletal muscle Dystrophin in zebrafish embryos revealed by improved FRAP analysis

“…Instead, the coding sequence is preceded by a standard chimaeric intron. While previous studies showed a role for 5′ and 3′ UTR regions into controlling tissue-specific expression and transcriptional regulation of Dystrophin (see Larsen and Howard, 2014 and references therein), our results show that UTR regions are dispensable for accumulation of the mRNA at the tip. It is therefore unlikely that Dystrophin RNA accumulation at the tips is due to specific RNA transport since that would most likely require the presence of the untranslated regions (for review see Kloc et al, 2002 ; Holt and Bullock, 2009 ).…”

Genome‐wide analysis of European sea bass provides insights into the evolution and functions of single‐exon genes

“…They may reflect the involvement of 5′UTR in mechanisms governing transcriptional regulation. Indeed, the longer 5′UTRs of SEGs may reflect lower translation rates compared with MEGs, in agreement with previous findings that mRNAs with high translation rates often contain short 5′UTRs (Larsen & Michael, 2014).…”

Variations in BCO2 Coding Sequence Causing a Difference in Carotenoid Concentration in the Skin of Chinese Indigenous Chicken

“…Despite our observations, one has to keep in mind that SNPs may not be the only cause of differences in BCO2 gene expression between the Qingjiao Ma and Guangxi Huang chicken breeds. There may be other factors that can be responsible for the reduced expression of the BCO2 gene expression in the Guangxi Huang chicken breed, such as DNA methylation [ 40 , 41 , 42 ], histone modification [ 43 , 44 , 45 ], and UTR function and, thus, translational modification [ 46 ]. Additional experiments need to be performed to elucidate the specific difference in BCO2 expression in the skin of Qingjiao Ma and Guangxi Huang chicken breeds without differences in gene expression in any other tissue.…”