@article{brillada_zheng_krueger_rovira-diaz_askani_schumacher_rojas-pierce_2018, title={Phosphoinositides control the localization of HOPS subunit VPS41, which together with VPS33 mediates vacuole fusion in plants}, volume={115}, ISSN={["0027-8424"]}, url={https://doi.org/10.1073/pnas.1807763115}, DOI={10.1073/pnas.1807763115}, abstractNote={The vacuole is an essential organelle in plant cells, and its dynamic nature is important for plant growth and development. Homotypic membrane fusion is required for vacuole biogenesis, pollen germination, stomata opening, and gravity perception. Known components of the vacuole fusion machinery in eukaryotes include SNARE proteins, Rab GTPases, phosphoinositides, and the homotypic fusion and vacuolar protein sorting (HOPS) tethering complex. HOPS function is not well characterized in plants, but roles in embryogenesis and pollen tube elongation have been reported. Here, we show that Arabidopsis HOPS subunits VPS33 and VPS41 accumulate in late endosomes and that VPS41, but not VPS33, accumulates in the tonoplast via a wortmannin-sensitive process. VPS41 and VPS33 proteins bind to liposomes, but this binding is inhibited by phosphatidylinosiltol-3-phosphate [PtdIns(3)P] and PtdIns(3,5)P2, which implicates a nonconserved mechanism for HOPS recruitment in plants. Inducible knockdown of VPS41 resulted in dramatic vacuole fragmentation phenotypes and demonstrated a critical role for HOPS in vacuole fusion. Furthermore, we provide evidence for genetic interactions between VPS41 and VTI11 SNARE that regulate vacuole fusion, and the requirement of a functional SNARE complex for normal VPS41 and VPS33 localization. Finally, we provide evidence to support VPS33 and SYP22 at the initial stage for HOPS-SNARE interactions, which is similar to other eukaryotes. These results highlight both conserved and specific mechanisms for HOPS recruitment and function during vacuole fusion in plants.}, number={35}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, publisher={Proceedings of the National Academy of Sciences}, author={Brillada, Carla and Zheng, Jiameng and Krueger, Falco and Rovira-Diaz, Eliezer and Askani, Jana Christin and Schumacher, Karin and Rojas-Pierce, Marcela}, year={2018}, month={Aug}, pages={EB305–EB314} }
 @misc{brillada_rojas-pierce_2017, title={Vacuolar trafficking and biogenesis: a maturation in the field}, volume={40}, ISSN={["1879-0356"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85028575104&partnerID=MN8TOARS}, DOI={10.1016/j.pbi.2017.08.005}, abstractNote={The vacuole is a prominent organelle that is essential for plant viability. The vacuole size, and its role in ion homeostasis, protein degradation and storage, place significant demands for trafficking of vacuolar cargo along the endomembrane system. Recent studies indicate that sorting of vacuolar cargo initiates at the ER and Golgi, but not the trans-Golgi network/early endosome, as previously thought. Furthermore, maturation of the trans-Golgi network into pre-vacuolar compartments seems to contribute to a major route for plant vacuolar traffic that works by bulk flow and ends with membrane fusion between the pre-vacuolar compartment and the tonoplast. Here we summarize recent evidence that indicates conserved and plant-specific mechanisms involved in sorting and trafficking of proteins to this major organelle.}, journal={CURRENT OPINION IN PLANT BIOLOGY}, publisher={Elsevier BV}, author={Brillada, Carla and Rojas-Pierce, Marcela}, year={2017}, month={Dec}, pages={77–81} }
 @article{alvarez_han_toyota_brillada_zheng_gilroy_rojas-pierce_2016, title={Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls}, volume={67}, ISSN={["1460-2431"]}, url={https://doi.org/10.1093/jxb/erw418}, DOI={10.1093/jxb/erw418}, abstractNote={Gravitropism in Arabidopsis shoots depends on the sedimentation of amyloplasts in the endodermis, and a complex interplay between the vacuole and F-actin. Gravity response is inhibited in zigzag-1 (zig-1), a mutant allele of VTI11, which encodes a SNARE protein involved in vacuole fusion. zig-1 seedlings have fragmented vacuoles that fuse after treatment with wortmannin, an inhibitor of phosphatidylinositol 3-kinase, and underscore a role of phosphoinositides in vacuole fusion. Using live-cell imaging with a vertical stage microscope, we determined that young endodermal cells below the apical hook that are smaller than 70 μm in length are the graviperceptive cells in dark-grown hypocotyls. This result was confirmed by local wortmannin application to the top of zig-1 hypocotyls, which enhanced shoot gravitropism in zig-1 mutants. Live-cell imaging of zig-1 hypocotyl endodermal cells indicated that amyloplasts are trapped between juxtaposed vacuoles and their movement is severely restricted. Wortmannin-induced fusion of vacuoles in zig-1 seedlings increased the formation of transvacuolar strands, enhanced amyloplast sedimentation and partially suppressed the agravitropic phenotype of zig-1 seedlings. Hypergravity conditions at 10 g were not sufficient to displace amyloplasts in zig-1, suggesting the existence of a physical tether between the vacuole and amyloplasts. Our results overall suggest that vacuole membrane remodeling may be involved in regulating the association of vacuoles and amyloplasts during graviperception.}, number={22}, journal={JOURNAL OF EXPERIMENTAL BOTANY}, publisher={Oxford University Press (OUP)}, author={Alvarez, Ashley Ann and Han, Sang Won and Toyota, Masatsugu and Brillada, Carla and Zheng, Jiameng and Gilroy, Simon and Rojas-Pierce, Marcela}, year={2016}, month={Dec}, pages={6459–6472} }