RT Journal Article
SR Electronic
T1 Intimate functional interactions between TGS1 and the Smn complex revealed by an analysis of the Drosophila eye development
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.02.06.936724
DO 10.1101/2020.02.06.936724
A1 Paolo Maccallini
A1 Francesca Bavasso
A1 Livia Scatolini
A1 Elisabetta Bucciarelli
A1 Gemma Noviello
A1 Veronica Lisi
A1 Valeria Palumbo
A1 Simone D’Angeli
A1 Stefano Cacchione
A1 Giovanni Cenci
A1 Laura Ciapponi
A1 James G. Wakefield
A1 Maurizio Gatti
A1 Grazia Daniela Raffa
YR 2020
UL http://biorxiv.org/content/early/2020/02/07/2020.02.06.936724.abstract
AB Trimethylguanosine synthase 1 (TGS1) is a conserved enzyme that mediates formation of the trimethylguanosine cap on several RNAs, including snRNAs and telomerase RNA. Previous studies have shown that TGS1 binds the Survival Motor Neuron (SMN) protein, whose deficiency causes spinal muscular atrophy (SMA). In addition, TGS1 depletion results in increased hTR levels and telomere elongation in human cells. Here, we analyzed the roles of the Drosophila orthologs of the human TGS1 and SMN genes. We show that the Drosophila TGS1 protein (dTgs1) physically interacts with all subunits of the Drosophila Smn complex (Smn, Gem2, Gem3, Gem4 and Gem5), and that a human TGS1 transgene rescues the mutant phenotype caused by dTgs1 loss. We demonstrate that both dTgs1 and Smn are required for viability of retinal progenitor cells and that downregulation of these genes leads to a reduced eye size. Importantly, overexpression of dTgs1 partially rescues the eye defects caused by Smn depletion, and vice versa. These results suggest that the Drosophila eye model can be exploited for screens aimed at the identification of genes and drugs that modify the phenotypes elicited by Tgs1 and Smn deficiency. These modifiers could help to devise new therapies for SMA and diseases caused by telomerase insufficiency.