Plant NETWORKED and VAP27 Proteins Work in Complexes to Regulate Membrane-Based Functions.

Abstract

Eukaryotic cells are subdivided into specialised organelle compartments, each with unique physiological environments and functions. Interaction and cross-talk between organelles is inherent to Eukaryotic life, and each organelle is physically interconnected to their surrounding subcellular components including the cytoskeleton and adjacent membrane compartments. In animals and yeast, the mechanisms of organelle interaction have been well characterised and are known to have fundamental importance to life. In contrast, we are only beginning to understand the mechanisms and functions of such interactions in plants. The discovery and ongoing characterisation of the NETWORKED (NET) protein family of plant actin-membrane adaptors has greatly advanced our understanding of the mechanisms of organelle-cytoskeletal interaction. Furthermore, unfolding investigation into the NET proteins has revealed their binding partner, VAMP-ASSOCIATED PROTEIN-27 (VAP27), to be a regulator of organelle tethering and interaction with previously unknown, specialised roles in plants. Research on NET and VAP27 proteins has rapidly increased our knowledge of the mechanisms regulating membrane interaction in plants, their functions in regulating cell structure and organisation, as well as their importance to plant growth, development and stress-response. Here, we discuss the discovery and characterisation of the NET and VAP27 proteins, their regulation of organelle interaction and their functions in plants.