Functional characterization reveals the importance of Arabidopsis ECA4 and EPSIN3 in clathrin mediated endocytosis and wall structure in apical growing cells.

Localized clathrin mediated endocytosis is vital for secretion and wall deposition in apical growing plant cells. Adaptor and signalling proteins, along with phosphoinositides, are known to play a regulatory, yet poorly defined role in this process. Here we investigated the function of Arabidopsis ECA4 and EPSIN3, putative mediators of the process, in pollen tubes and root hairs.

Mitophagy in plants: Emerging regulators of mitochondrial targeting for selective autophagy.

The degradation and turnover of mitochondria is fundamental to Eukaryotes and is a key homeostatic mechanism for maintaining functional mitochondrial populations. Autophagy is an important pathway by which mitochondria are degraded, involving their sequestration into membrane-bound autophagosomes and targeting to lytic endosomal compartments (the lysosome in animals, the vacuole in plants and yeast). Selective targeting of mitochondria for autophagy, also known as mitophagy, distinguishes mitochondria from other cell components for degradation and is necessary for the regulation of mitochondria-specific cell processes.

NET4 and RabG3 link actin to the tonoplast and facilitate cytoskeletal remodelling during stomatal immunity.

Members of the NETWORKED (NET) family are involved in actin-membrane interactions. Here we show that two members of the NET family, NET4A and NET4B, are essential for normal guard cell actin reorganization, which is a process critical for stomatal closure in plant immunity. NET4 proteins interact with F-actin and with members of the Rab7 GTPase RABG3 family through two distinct domains, allowing for simultaneous localization to actin filaments and the tonoplast.

Membrane contact sites and cytoskeleton-membrane interactions in autophagy.

In Eukaryotes, organelle interactions occur at specialised contact sites between organelle membranes. Contact sites are regulated by specialised tethering proteins, which bring organelle membranes into close proximity, and facilitate functional crosstalk between compartments. While contact site proteins are well characterised in mammals and yeast, the regulators of plant contact site formation are only now beginning to emerge.