@article{22647,
  abstract     = {Within the plant endomembrane system, the vesicle coat protein clathrin localizes to the plasma membrane (PM) and the trans-Golgi Network/early endosome (TGN/EE). While the role of clathrin in endocytosis at the PM is well established, its function at TGN/EE, presumably in late secretion (trafficking from the TGN/EE to the cell surface) or en route to the vacuole, is debated. Similarly debated are potential homeostatic mechanisms balancing the trafficking routes, especially endocytosis and late secretion.
We address these questions in Arabidopsis thaliana using conditional silencing of CLATHRIN HEAVY CHAIN (CHC), conditional overexpression of the clathrin uncoating factor AUXILIN-LIKE1, and secretory mutants.
CHC silencing interferes with trafficking of cargoes destined for the apoplast and the PM, supporting a function of clathrin in late secretion. The secretory cargoes become abnormally rerouted from the TGN/EE to the vacuole. Unlike CHC silencing, overexpression of AUXILIN-LIKE1 selectively inhibits clathrin-mediated endocytosis while secretion continues normally at early points of induction. Conversely, secretory mutants exhibit a reduced PM recruitment of clathrin, and variably, of the TPLATE endocytic component.
Together, our data show a role of clathrin in secretion and suggest secretion as a fundamental trafficking process to which endocytosis is adjusted by a weak homeostatic mechanism.},
  author       = {Adamowski, Maciek and Gackowski, Adam and Matijevic, Ivana and Alotaibi, Saqer S. and Friml, Jiří},
  issn         = {1469-8137},
  journal      = {New Phytologist},
  publisher    = {Wiley},
  title        = {{The role of clathrin in post‐Golgi secretion in plant cells}},
  doi          = {10.1111/nph.71454},
  year         = {2026},
}

@article{15033,
  abstract     = {The GNOM (GN) Guanine nucleotide Exchange Factor for ARF small GTPases (ARF-GEF) is among the best studied trafficking regulators in plants, playing crucial and unique developmental roles in patterning and polarity. The current models place GN at the Golgi apparatus (GA), where it mediates secretion/recycling, and at the plasma membrane (PM) presumably contributing to clathrin-mediated endocytosis (CME). The mechanistic basis of the developmental function of GN, distinct from the other ARF-GEFs including its closest homologue GNOM-LIKE1 (GNL1), remains elusive. Insights from this study largely extend the current notions of GN function. We show that GN, but not GNL1, localizes to the cell periphery at long-lived structures distinct from clathrin-coated pits, while CME and secretion proceed normally in <jats:italic>gn</jats:italic> knockouts. The functional GN mutant variant GN<jats:sup>fewerroots</jats:sup>, absent from the GA, suggests that the cell periphery is the major site of GN action responsible for its developmental function. Following inhibition by Brefeldin A, GN, but not GNL1, relocates to the PM likely on exocytic vesicles, suggesting selective molecular associations en route to the cell periphery. A study of GN-GNL1 chimeric ARF-GEFs indicates that all GN domains contribute to the specific GN function in a partially redundant manner. Together, this study offers significant steps toward the elucidation of the mechanism underlying unique cellular and development functions of GNOM.},
  author       = {Adamowski, Maciek and Matijevic, Ivana and Friml, Jiří},
  issn         = {2050-084X},
  journal      = {eLife},
  keywords     = {General Immunology and Microbiology, General Biochemistry, Genetics and Molecular Biology, General Medicine, General Neuroscience},
  publisher    = {eLife Sciences Publications},
  title        = {{Developmental patterning function of GNOM ARF-GEF mediated from the cell periphery}},
  doi          = {10.7554/elife.68993},
  volume       = {13},
  year         = {2024},
}

@article{15374,
  abstract     = {Clathrin-mediated endocytosis (CME) is an essential process of cargo uptake operating in all eukaryotes. In animals and yeast, BAR-SH3 domain proteins, endophilins and amphiphysins, function at the conclusion of CME to recruit factors for vesicle scission and uncoating. Arabidopsis thaliana contains the BAR-SH3 domain proteins SH3P1–SH3P3, but their role is poorly understood. Here, we identify SH3Ps as functional homologs of endophilin/amphiphysin. SH3P1–SH3P3 bind to discrete foci at the plasma membrane (PM), and SH3P2 recruits late to a subset of clathrin-coated pits. The SH3P2 PM recruitment pattern is nearly identical to its interactor, a putative uncoating factor, AUXILIN-LIKE1. Notably, SH3P1–SH3P3 are required for most of AUXILIN-LIKE1 recruitment to the PM. This indicates a plant-specific modification of CME, where BAR-SH3 proteins recruit auxilin-like uncoating factors rather than the uncoating phosphatases, synaptojanins. SH3P1–SH3P3 act redundantly in overall CME with the plant-specific endocytic adaptor TPLATE complex but not due to an SH3 domain in its TASH3 subunit.},
  author       = {Adamowski, Maciek and Randuch, Marek and Matijevic, Ivana and Narasimhan, Madhumitha and Friml, Jiří},
  issn         = {2211-1247},
  journal      = {Cell Reports},
  number       = {5},
  publisher    = {Cell Press},
  title        = {{SH3Ps recruit auxilin-like vesicle uncoating factors for clathrin-mediated endocytosis}},
  doi          = {10.1016/j.celrep.2024.114195},
  volume       = {43},
  year         = {2024},
}

@article{12163,
  abstract     = {Small GTPases play essential roles in the organization of eukaryotic cells. In recent years, it has become clear that their intracellular functions result from intricate biochemical networks of the GTPase and their regulators that dynamically bind to a membrane surface. Due to the inherent complexities of their interactions, however, revealing the underlying mechanisms of action is often difficult to achieve from in vivo studies. This review summarizes in vitro reconstitution approaches developed to obtain a better mechanistic understanding of how small GTPase activities are regulated in space and time.},
  author       = {Loose, Martin and Auer, Albert and Brognara, Gabriel and Budiman, Hanifatul R and Kowalski, Lukasz M and Matijevic, Ivana},
  issn         = {1873-3468},
  journal      = {FEBS Letters},
  keywords     = {Cell Biology, Genetics, Molecular Biology, Biochemistry, Structural Biology, Biophysics},
  number       = {6},
  pages        = {762--777},
  publisher    = {Wiley},
  title        = {{In vitro reconstitution of small GTPase regulation}},
  doi          = {10.1002/1873-3468.14540},
  volume       = {597},
  year         = {2023},
}