Dynamin-related proteins in plant post-Golgi traffic

Abstract

Membrane traffic between two organelles begins with the formation of transport vesicles from the donor organelle. Dynamin-related proteins (DRPs), which are large multidomain GTPases, play crucial roles in vesicle formation in post-Golgi traffic. Numerous in vivo and in vitro studies indicate that animal dynamins, which are members of DRP family, assemble into ring- or helix-shaped structures at the neck of a bud site on the donor membrane, where they constrict and sever the neck membrane in a GTP hydrolysis-dependent manner. While much is known about DRP-mediated trafficking in animal cells, little is known about it in plant cells. So far, two structurally distinct subfamilies of plant DRPs (DRP1 and DRP2) have been found to participate in various pathways of post-Golgi traffic. This review summarizes the structural and functional differences between these two DRP subfamilies, focusing on their molecular, cellular and developmental properties. We also discuss the molecular networks underlying the functional machinery centering on these two DRP subfamilies. Furthermore, we hope that this review will provide direction for future studies on the mechanisms of vesicle formation that are not only unique to plants but also common to eukaryotes.

Intersection of endocytic and exocytic systems in Toxoplasma gondii

“…DrpB promotes exocytic trafficking of a subset of microneme and rhoptry proteins, but significant colocalization of ingested protein with DrpB suggests that DrpB could also be involved in endocytic trafficking in T. gondii. Dynamins are guanine triphosphatases (GTPases) best known for their role in fission of endocytic vesicles forming at plasma membrane into the cytosol, but can also promote membrane fission at the TGN, endosomes and mitochondria T. gondii DrpB localizes to the TGN and potentially the ELCs, but has not been observed at the parasite plasma membrane . However, given that dynamin‐dependent fission of endocytic vesicles at the plasma membrane is conserved in plants, mammals, fungi and other protozoan parasites including Plasmodium, transient populations of DrpB that are difficult to detect by traditional microscopy could promote endocytosis at the plasma membrane similar to the yeast dynamin‐like protein Vps1 .…”

“…Therefore, endocytic trafficking of ingested host proteins intersects with exocytic trafficking to micronemes, but not to rhoptries, suggesting that rhoptry trafficking may diverge earlier in the endolysosomal system such as the TGN or occupy functionally distinct ELCs. forming at plasma membrane into the cytosol, but can also promote membrane fission at the TGN, endosomes and mitochondria 43,44 T. gondii DrpB localizes to the TGN and potentially the ELCs, but has not been observed at the parasite plasma membrane. 9,12 However, into the PV lumen, depletion of microneme and rhoptry organelles and non-invasive parasites.…”

“…given that dynamin-dependent fission of endocytic vesicles at the plasma membrane is conserved in plants, mammals, fungi and other protozoan parasites including Plasmodium,[43][44][45][46][47] transient populations of DrpB that are difficult to detect by traditional microscopy could promote endocytosis at the plasma membrane similar to the yeast dynamin-like protein Vps1. 46 If this is true, then interfering with DrpB function will inhibit ingestion and reduce the percentage of mCherry + parasites.…”

Inroads into Internalization: Five Years of Endocytic Exploration

“…Like the DRP2s, the DRP1s are essential; in Arabidopsis, DRP1A, DRP1C, and DRP1E are required for various stages of plant development, including pollen maturation, embryogenesis, seedling growth, and fertilization, and mutants display cell plate and PM biogenesis defects (Kang et al, 2003;Konopka and Bednarek, 2008a;Fujimoto and Tsutsumi, 2014). Consistent with their function in endocytosis, DRP1s colocalize with clathrin in dynamic PM CCPs (Konopka et al, 2008;Fujimoto et al, 2010), and drp1 mutants display abnormal CME (Collings et al, 2008).…”

“…Overcoming the thermodynamic energy barrier necessary for scission of the vesicle from the PM requires the coordinated activity of a number of EAPs, including dynamin, amphiphysin, and endophilins (Antonny et al, 2016). In plants, CME is dependent on the function of two DRP families: the DRP2 family that is the most similar to metazoan dynamin as well as the plant-specific DRP1 family Fujimoto and Tsutsumi, 2014).…”