A novel family of plant nuclear envelope associated proteins

Pawar, V; Poulet, A; Detourne, G; Tatout, C; Vanrobays, E; Evans, D; Graumann, K

Journal Article

A novel family of plant nuclear envelope associated proteins

Abstract

This paper describes the characterisation of a new family of higher plant nuclear envelope associated proteins (NEAPs) that interact with proteins of the nuclear envelope. In the model plant Arabidopsis thaliana, the family consists of three genes expressed ubiquitously (AtNEAP1-3) and a pseudogene (AtNEAP4). NEAPs consist of extensive coiled-coil domains, followed by a nuclear localisation signal and a C-terminal predicted transmembrane domain. Domain deletion mutants confirm the presence of a functional nuclear localisation signal and transmembrane domain. AtNEAP proteins localise to the nuclear periphery as part of stable protein complexes, are able to form homo- and heteromers and interact with the SUN domain proteins AtSUN1 and AtSUN2, involved in the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex. An A. thaliana cDNA library screen identified a putative transcription factor called AtbZIP18 as a novel interactor of AtNEAP1, which suggest a connection between NEAP and chromatin. An Atneap1 Atneap3 double knock out mutant showed reduced root growth and altered nuclear morphology and chromatin structure. Thus AtNEAPs are suggested as INM anchored coiled-coil proteins with roles in maintaining nuclear morphology and chromatin structure.