Journal Article

Sumoylation regulates the assembly and activity of the SMN complex

Rinchetti, Paola, Mentis, George Z., Hao, Le Thi, Riboldi, Giulietta M., Faravelli, Irene, Beattie, Christine C., Delestrée, Nicolas, Dermentzaki, Georgia, Kuwajima, Takaaki, Lotti, Francesco, Corti, Stefania, De Planell-Saguer, Mariangels, Przedborski, Serge

2021

Overview

SMN is a ubiquitously expressed protein and is essential for life. SMN deficiency causes the neurodegenerative disease spinal muscular atrophy (SMA), the leading genetic cause of infant mortality. SMN interacts with itself and other proteins to form a complex that functions in the assembly of ribonucleoproteins. SMN is modified by SUMO (Small Ubiquitin-like Modifier), but whether sumoylation is required for the functions of SMN that are relevant to SMA pathogenesis is not known. Here, we show that inactivation of a SUMO-interacting motif (SIM) alters SMN sub-cellular distribution, the integrity of its complex, and its function in small nuclear ribonucleoproteins biogenesis. Expression of a SIM-inactivated mutant of SMN in a mouse model of SMA slightly extends survival rate with limited and transient correction of motor deficits. Remarkably, although SIM-inactivated SMN attenuates motor neuron loss and improves neuromuscular junction synapses, it fails to prevent the loss of sensory-motor synapses. These findings suggest that sumoylation is important for proper assembly and function of the SMN complex and that loss of this post-translational modification impairs the ability of SMN to correct selective deficits in the sensory-motor circuit of SMA mice. Sumoylation is important for the assembly and function of the SMN complex, which plays a central role in RNA processing. Here the authors show that loss of this posttranslational modification impairs the ability of SMN to correct selective deficits in the sensory-motor circuit of animal models of spinal muscular atrophy.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 13/1 / 13/106 / 13/109 / 13/51 / 13/89 / 14/63 / 42 / 631/378/1689 / 631/80/458/538 / 82/29 / 82/51 / 82/83 / Animal models / Assembly / Atrophy / Biosynthesis / Circuits / Deactivation / Enzymes / Humanities and Social Sciences / Inactivation / Infant mortality / Kinases / Localization / multidisciplinary / Neurodegenerative diseases / Neuromuscular diseases / Neurosciences / Pathogenesis / Post-translation / Proteins / Ribonucleoproteins / Ribonucleoproteins (small nuclear) / RNA processing / Science / Science (multidisciplinary) / SMN protein / Spinal muscular atrophy / SUMO protein / Survival / Synapses / Ubiquitin