Clustering of a kinesin-14 motor enables processive retrograde microtubule-based transport in plants

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Plants 1 (2015): 15087, doi:10.1038/nplants.2015.87.The molecular motors kinesin and dynein drive bidirectional motility along microtubules (MTs) in most eukaryotic cells1,2. Land plants, however, are a notable exception, since they contain a large number of kinesins but lack cytoplasmic dynein, the foremost processive retrograde transporter3,4. It remains unclear how plants achieve retrograde cargo transport without dynein. Here, we have analyzed the motility of the six members of minus-end-directed kinesin-14 motors in the moss Physcomitrella patens and found that none are processive as native dimers. However, when artificially clustered into as little as dimer of dimers, the type-VI kinesin-14 (a homologue of Arabidopsis KCBP [kinesin-like calmodulin binding protein]) exhibited highly processive and fast motility (up to 0.6 μm/s). Multiple kin14-VI dimers attached to liposomes also induced transport of this membrane cargo over several microns. Consistent with these results, in vivo observations of GFP-tagged kin14-VI in moss cells revealed fluorescent punctae that moved processively towards the minus ends of the cytoplasmic MTs. These data suggest that clustering of a kinesin-14 motor serves as a dynein-independent mechanism for retrograde transport in plants.This work was supported by the Human Frontier Science Program, the James A. and Faith Miller Memorial Fund (MBL), the Laura and Arthur Colwin Endowed Summer Research Fellowship Fund (MBL), the TORAY Science Foundation, Grants-in-Aid for Scientific Research (15K14540, MEXT) (G.G), and the NIH (38499; R.D.V).2015-12-2

Thermodynamic Properties of Tetra-n-butylphosphonium Dicarboxylate Semiclathrate Hydrates

Semiclathrate hydrate (SCH) is one of the phase change materials suitable for cold energy storage. Thermodynamic properties of SCHs, such as an equilibrium temperature and the dissociation enthalpy, depend on the size and shape of the guest substances. In the present study, to reveal the effects of steric conformations of the guest anions on the thermodynamic properties of SCHs, tetra-n-butylphosphonium dicarboxylate (TBP-DC) SCHs, where the anion was oxalate (TBP-Oxa), malonate (TBP-Mal), succinate (TBP-Suc), glutarate (TBP-Glu), maleate (TBP-Male), or fumarate (TBP-Fum), were investigated. TBP-Oxa, -Mal, -Suc, and -Fum SCHs had similar equilibrium temperatures, whereas the equilibrium temperatures of TBP-Glu and -Male SCHs were higher. This suggests that the size and conformation of glutarate and maleate anions are appropriate for the cage structures of SCHs. Moreover, we compared the equilibrium temperatures of TBP-Suc, -Male, and -Fum SCHs because TBP-Suc, -Male, and -Fum have similar anion structures. The equilibrium temperature of TBP-Suc SCH was similar to that of TBP-Fum SCH, whereas TBP-Male SCH showed a higher equilibrium temperature. This result implies that the succinate anion is accommodated in the trans conformation, similar to the fumarate anion, in the hydrate cages.Jin Shimada, Moe Yamada, Atsushi Tani et al. Thermodynamic Properties of Tetra-n-butylphosphonium Dicarboxylate Semiclathrate Hydrates. Journal of Chemical & Engineering Data, 67 (1), 67-73, January 13, © 2022 American Chemical Society. https://doi.org/10.1021/acs.jced.1c0074

Modeling of the Fukushima Daiichi Nuclear Power Plant Derived Radioactive Cesium Dynamics in Grazing Grassland

The damage to the Fukushima Daiichi Nuclear Power Plant incurred following the Great East Japan Earthquake and tsunami on March 11, 2011 resulted in serious radioactive pollution of Eastern Japan. In some grasslands of this area, radioactive cesium (Cs) content of grasses exceeded the provisional safety standard for use as feed for dairy and beef cattle of 100 Bq kg–1 fresh weight, and the livestock industry has been seriously affected in numerous ways: needing to dispose of polluted forage, grazing prohibitions, declines in beef prices, suspensions of shipping beef to market, and blanket testing of beef cattle (Manabe et al., 2013). The spatial distribution of radioactive Cs in grasslands was complex in various scales (Tsuiki and Maeda, 2012a; 2012b). So it is difficult to estimate actual pollution level in grassland ecosystems. The transfer of radioactive Cs from soil to plant is affected by soil soluble potassium (K) concentration, pH, clay and organic matter contents (Absalom et al., 2001; Tsuiki et al., 2013). The radioactive Cs dynamics in soil-plantanimal system is complex and modeling is necessary to clarify the relationships. In this study, a model of radioactive Cs dynamics in Zoysia japonica Steud. dominated grazing grassland was developed to predict radioactive Cs concentration of grass and grazing cattle

Developing Microsurgery through Experience in Yangon General Hospital, Myanmar

Although many surgical centers perform microsurgery routinely in developed countries, performing microsurgery is challenging in resource-poor developing countries, such as Myanmar. With the establishment of educational training programs and the assistance of volunteer plastic surgical teams, local plastic surgeons can learn the techniques of microsurgery and apply them clinically. The purpose of this study was to establish baseline data and define the challenges of performing microsurgery in Yangon General Hospital, Myanmar. Sixty-four patients underwent reconstruction with free flaps from January 2015 to January 2018. All clinical records of these cases were assessed. The number of free flap reconstructions performed increased from 11 in the first year to 24 in the third year. The anterolateral thigh flap was the most commonly used (42%). The most common sites of reconstruction were mandible and intraoral defects. Total flap survival occurred in 58 of 64 patients (89%). The total salvageable flap rate for revision surgery was 66.6%; the successful revision rate was highest in 2017, with fewer complications. The flap salvage rates increased and the operative duration decreased as clinical experience improved. Establishing a microsurgical center requires a strong multidisciplinary team, clinical experience, continuous learning, sensible clinical application, and effective interdepartmental and intradepartmental cooperation

Concentration of mitochondrial DNA mutations by cytoplasmic transfer from platelets to cultured mouse cells

Accumulation of mutations in mitochondrial DNA (mtDNA) is thought to be responsible for mitochondrial, and other, diseases and biological phenomena, such as diabetes, cancer, neurodegenerative diseases, and aging. Mouse models may elucidate the relationship between mutations in mtDNA and these abnormalities. However, because of the difficulty of mtDNA manipulation, generation of mouse models has not sufficiently progressed to enable such studies. To overcome this difficulty and to establish a source of diverse mtDNA mutations, we here generated cultured mouse cells containing mtDNA derived from an mtDNA mutator mouse that accumulates random mtDNA mutations with age. Mutation analysis of the obtained transmitochondrial cytoplasmic hybrid cells (cybrids) revealed that the cells harbored diverse mtDNA mutations occurring at a higher frequency than in mouse tissues, and exhibited severe respiration defects that would be lethal in tissues or organs. Abnormal respiratory complex formation and high stress on the mitochondrial protein quality control system appeared to be involved in these severe respiration defects. The mutation rates of the majority of highly accumulated mutations converged to either approximately 5%, 10%, or 40%, suggesting that these mutations are linked on the respective mtDNA molecules, and mtDNA in cybrid cells likely consisted of mtDNA molecules clonally expanded from the small population of introduced mtDNAs. Thus, the linked mutations in these cybrid cells cannot be evaluated individually. In addition, mtDNA mutations homologous to confirmed pathogenic mutations in human were rarely observed in our generated cybrids. However, the transmitochondrial cybrids constitute a useful tool for concentrating pathogenic mtDNA mutations and as a source of diverse mtDNA mutations to elucidate the relationship between mtDNA mutations and diseases

Ligulate Desmarestia (Desmarestiales, Phaeophyceae) revisited : D. japonica sp. nov. and D. dudresnayi differ from D. ligulata

Funded by Korea Research Foundation UK Natural Environment Research Council Molecular Bioanalytics Facility. Grant Number: MGF-154 Natural Environment Research Council. Grant Number: 2025 NF3 German Academic Merit Foundation European Commission The Marine Alliance for Science and Technology for Scotland Scottish Funding Council. Grant Number: HR09011Peer reviewedPostprintPostprintPostprin

Different PDGF Receptor Dimers Drive Distinct Migration Modes of the Mouse Skin Fibroblast

Background/Aims: The migration of mesenchymal cells is a fundamental cellular process that has been implicated in many pathophysiological conditions and is induced by chemoattractants such as platelet-derived growth factors (PDGFs). However, the regulatory mechanisms shaping this migration remain to be elucidated. Methods: Here, we prepared mouse skin fibroblasts inactivated for different PDGF receptor genes and systematically measured their chemotactic responses within a gradient of different chemoattractants. Results: We found that PDGFRαβ and PDGFRββ dimers were strong inducers of random and directionally-persistent migration, respectively, that was sustained for up to 24 h. MAPK and PI3K were necessary to mediate random and directional migration, respectively. Directional migration was accompanied by abundant ventral stress fiber formation and consistent cell shape with less frequent formation of branch-like processes. Conclusion: This is the first systematic study that characterized the chemotaxis mediated by three-different types of PDGFR dimers in mesenchymal cell migration. Our data demonstrate that PDGFR dimer formation is the critical step to determine the specific mode of fibroblast chemotaxis, while the accompanying cytoskeletal remodeling might contribute to migration persistence

Heliocentric Distance Dependence of Zodiacal Light Observed by Hayabusa2#

Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as $n(r) \sim r^{-\alpha}$, and the exponent $\alpha \sim 1.3$ was obtained by previous observations from interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of $\alpha$ based on ZL observations from interplanetary space outside Earth's orbit have been performed since then. Here, we introduce initial results for the radial profile of the ZL at optical wavelengths observed over the range 0.76-1.06 au by ONC-T aboard the Hayabusa2# mission in 2021-2022. The ZL brightness we obtained is well reproduced by a model brightness, although there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The radial power-law index we obtained is $\alpha = 1.30 \pm 0.08$, which is consistent with previous results based on ZL observations. The dominant source of uncertainty arises from the uncertainty in estimating the diffuse Galactic light (DGL).Comment: 22 pages, 19 figures, 4 tables, accepted for publication by Earth, Planets and Spac

Electromagnetic fields in biological studies

For biological or cellular experiments using electromagnetic fields, it is essential that the parameters defining the field be carefully specified if the results are to be meaningful and are to be compared with the same experiment conducted in a different laboratory. The interaction of living systems with electric and magnetic fields can come only through forces exerted on the charges on the system. If the charges are stationary, the only origin of the force is the electric field. This electric field may be established by charge distributions, as in “capacitive plate” experiments, or by time-varying magnetic fields.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43995/1/10439_2006_Article_BF00000002.pd

On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective

Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10’s of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation