SECUAH 2018 > Limón etal 2018

dianas | Vol 7 No 1 | 2018 | e201803

On the role of Arabidopsis thaliana Nuclear Envelope-associated proteins in DNA repair

José Carlos Limón, Mónica Pradillo, Juan Luis Santos

Departamento de Genética de la Universidad Complutense de Madrid

josec.limon@hotmail.com

III Congreso de Señalización Celular, SECUAH 2018.
20-22 de marzo, 2018. Universidad de Alcalá. Alcalá de Henares, Madrid. España.
Sesión

Abstract

The nuclear envelope (NE) is a multifunctional platform involved in different processes such as nuclear transport, mechanotransduction, genome reorganization and DNA integrity maintenance. At the structural level, the NE presents an outer nuclear membrane (ONM) and an inner nuclear membrane (INM) separated by a perinuclear space. There are distinct proteins embedded within both membranes that connect the nucleus and the cytoplasm. Among them, LINC complexes, composed of the outer KASH and inner SUN nuclear membrane proteins, link the chromosomes with components of the cytoskeleton, whereas Nuclear Pore Complexes (NPCs), formed by multiple nucleoporins, play an essential role in the nucleocytoplasmic transport. The aim of this study is to determine the possible participation of SUN proteins and nucleoporins in DNA repair mechanisms using Arabidopsis thaliana as a working model. For doing this purpose, mutant plants for the corresponding genes were exposed to several genotoxic agents (cisplatin, mitomycin C, gamma-rays and UV-C radiation) that produce different types of DNA lesions. In addition, the expression levels of the critical genes involved in the different DNA repair pathways were analysed by qPCR. The results suggested that mutants deficient in SUN proteins and also in the plant-specific nucleoporin NUP136 are hypersensitive to agents that cause DNA double-strand breaks (DSBs). Furthermore, the qPCR analyses confirmed that the expression of genes involved in Homologous Recombination (HR), and some of those involved in Non-Homologous End Joining (NHEJ) were overexpressed in the mutants respect to wild type plants. The function of these NE-associated proteins in specific DNA repair pathways and chromatin dynamics will be discussed.