Department of Biological and Medical Sciences

Projects

  • 1. Investigating the SUN domain protein family at the plant NE


    The Sad1-Unc84 (SUN) domain family consists of two main groups – the classical C-terminal SUN domain proteins and the mid-SUN proteins. Members of the two groups interact with each other but the mid-SUN proteins remain poorly characterised so current
    work is focussing on these. Our research is supported by a collaboration with Prof Christophe Tatout, Clermont University, France.

    2. Protein interaction networks at the plant NE


    In addition to SUN proteins interacting with each other, various NE integral and associated proteins are being examined as putative SUN interaction partners. One group of proteins that is under investigation are Nuclear Envelope Associated Proteins (NEAPs) 1, 2 and 3. Further, Klarsicht/Anc1/Syne1 homology (KASH) domain proteins are the classical interactors of SUN proteins. In animal and yeast, the SUN-KASH complexes form bridges across the NE that directly link the cytoskeleton with the nucleoskeleton and chromatin. These nucleo-cytoskeletal bridging complexes are essential for chromatin organisation in interphase and division, nuclear shape as well as positioning and movement of the nucleus in response to external stimuli. A nucleoskeletal component interacting with SUNs in plants was identified to be CRWN/NMCP1 protein in our group. In addition, we also try to identify the SUN interactors by screening cDNA libraries in a membrane bound yeast two hybrid system and co-immunoprecipitation. The aim is to piece together a network of protein interactions based on SUN proteins at the plant NE and identifying novel plant NE proteins. This work is carried out together with Prof Tatout and Prof Iris Meier, Ohio State University.

    3. Mechanisms for the targeting and retention of inner nuclear envelope proteins

    Using chimaeric fluorescent constructs of the human lamin B receptor and plant NE proteins we have undertaken studies of the mechanisms, conserved between kingdoms, that permit targeting to the plant nuclear envelope. Using data obtained from mutants in which key targeting and binding domains have been deleted, we developed a model for inner nuclear envelope location of proteins in plants and are continuing this work with native plant proteins.

    4. Localisation and function of novel nuclear envelope proteins in plants

    Using a bioinformatics approach we have identified homologues of animal and yeast nuclear envelope proteins in plants and, with our collaborators are continuing to expand knowledge of the higher plant proteome. We first characterised proteins containing SUN domains as part of the plant LINker of Nucleoskeleton and Cytoskeleton (LINC) complex in plants as well as plant-specific NEAPs. We continued to identify binding partners and to characterise the function of the complexes in plants.