IZUMITSU Kosuke

写真a

Title

Lecturer

Campus Career 【 display / non-display

  • University of Shiga Prefecture  School of Environmental Science  Department of Biological Resources Management  Lecturer   2019.04 - Now

  • University of Shiga Prefecture  School of Environmental Science  Department of Biological Resources Management  Assistant Professor   2013.04 - 2019.03

 

Papers 【 display / non-display

  • An adaptor protein BmSte50 interacts with BmSte11 MAPKKK and is involved in host infection, conidiation, melanization, and sexual development in Bipolaris maydis

    Sumita T., Izumitsu K., Shigeyoshi S., Gotoh S., Yoshida H., Tsuji K., Yoshida H., Kitade Y., Tanaka C.

    Mycoscience  Mycoscience  61 (2)   85 - 94  2020.03

    10.1016/j.myc.2019.10.003  Joint Work  

    [Abstract]

    © 2019 The Mycological Society of Japan A mitogen-activated protein kinase (MAPK) signaling pathway regulates specialized cellular responses to external stimuli. In Bipolaris maydis, a Chk1 MAPK orthologous to Fus3/Kss1 MAPKs of Saccharomyces cerevisiae is known to regulate various developmental processes, including the formation of appressoria. However, upstream factors that regulate the Chk1 cascade have not been well clarified. In this study, we identified and characterized the BmSte50 gene, an ortholog of the yeast Ste50 in B. maydis. Our yeast two-hybrid assay indicated that BmSte50 interacts with a MAPK kinase kinase BmSte11, a component of the Chk1 cascade. ΔBmSte50 strains exhibited a loss of pathogenicity due to a lack of appressorial formation. The mutants also showed a reduction in melanization, conidial production, and aerial-mycelial and sexual development. Such phenotypes of the mutants were consistent with those of the Chk1 cascade gene mutants previously reported. In addition, ΔBmSte50 strains indicated lower conidial germination efficiency than the wild type. Notably, a significant number of ΔBmSte50 conidia could be germinated, while the Chk1 cascade gene mutants were reported to lack conidial germination ability. Our results suggested that BmSte50 may act as an adaptor protein for the Chk1 cascade and is involved in the regulation of various cellular processes.

  • Cla4 PAK-like kinase is required for pathogenesis, asexual/sexual development and polarized growth in Bipolaris maydis

    Kitade Y., Sumita T., Izumitsu K., Tanaka C.

    Current Genetics  Current Genetics  65 (5)   1229 - 1242  2019.10

    10.1007/s00294-019-00977-9  Joint Work  

    [Abstract]

    © 2019, Springer-Verlag GmbH Germany, part of Springer Nature. PAK (p21-activated protein kinases)-like kinases are master regulators of development and morphogenesis, which were conserved among eukaryotes, including fungi. In budding yeast, two types of PAK-like kinases, Ste20 and Cla4 have distinct but shared roles in the regulation of pseudohyphal development, budding and mating. In this study, to examine the broad functions of PAK-like kinases in growth, pathogenicity and asexual/sexual reproduction in filamentous fungi, we identified and characterized two PAK-like kinases, Ste20 and Cla4 in Bipolaris maydis. A single mutant of both Ste20 and Cla4 gene was viable, while the double mutant was not available, possibly because of lethality. In growth, conidiation, and pathogenicity, Δste20 strains showed phenotypes similar to those of the wild-type, while Δcla4 strains showed severely defected phenotypes. In this study, we also clarified that Ste20 is partially involved in pseudothecium development but is dispensable for maternity, while Cla4 is essential for maternal pseudothecium development and also involve in ascospore development in paternal pseudothecium. Fluorescent microscopy visualized the disorder in cell polarity at the hyphal tip in Δcla4. These results suggested that not Ste20 but Cla4 is a master regulator of growth, pathogenicity and asexual/sexual development in B. maydis. In addition, we successfully visualized alternation of branching pattern and distribution of Spitzenkörper at the hyphal tip in Δcla4 strains.

  • Priming effect of the addition of maize to a Japanese volcanic ash soil and its temperature sensitivity: a short-term incubation study

    Iimura Y., Tabara I., Izumitsu K., Fujitake N.

    Soil Science and Plant Nutrition  Soil Science and Plant Nutrition  65 (5)   444 - 450  2019.09

    10.1080/00380768.2019.1665969  Joint Work  

    [Abstract]

    © 2019, © 2019 Japanese Society of Soil Science and Plant Nutrition. The response of soil organic matter (SOM) to global warming is a crucial subject. However, the temperature sensitivity of SOM turnover remains largely uncertain. Changes in the mineralization of native SOM, i.e., priming effect (PE) may strongly affect the temperature sensitivity of SOM turnover in the presence of global warming. We investigated the direction and magnitude of the PE in a Japanese volcanic ash soil at different temperatures (15°C, 25°C, and 35°C) using a natural 13C tracer (C4-plant, maize leaf) in a short-term (25 days) incubation study. In addition, we evaluated the temperature sensitivity expressed as Q10 value with and without the addition of maize to the soil and their relations to PE. We found that positive PE occurred at each temperature condition and tended to increase with decreased temperature, and these PE results were consistent with the microbial biomass at the end of the incubation period. CO2 emission from control soil (without maize) increased with increasing temperature (Q10 = 2.6), but CO2 emission from the soil with added maize did not significantly change with increasing temperature (Q10 = 1.0). This was caused by the suppression of CO2 emission from the soil with increasing temperature (Q10 = 0.9). On the other hand, soil-originated CO2 emission clearly increased with increasing temperature (Q10 = 3.4) when Q10 values were calculated on the assumption that the temperature and substrate supply increase at the same time (from 25°C). These results suggest that not only the temperature increase but also the labile carbon supply may be important for the temperature sensitivity of Japanese volcanic ash soil.

  • Effects of overexpression of PKAc genes on expressions of lignin-modifying enzymes by Pleurotus ostreatus.

    Toyokawa C., Shobu M., Tsukamoto R., Okamura S., Honda Y., Kamitsuji H., Izumitsu K., Suzuki K., Irie T.

     Biosci Biotechnol Biochem    2016.03

    Joint Work  Joint(The vice charge)

  • A serine/threonine kinase gene BcATG1 is involved in conidiation and sclerotial development in Botrytis cinerea.

    Sumita T., K. Izumitsu, C. Tanaka

     Mycoscience  57   107 - 117  2016.01

    Joint Work  Joint(The vice charge)

  • Effects of calmodulin on expression of lignin-modifying enzymes in Pleurotus ostreatus.

    Suetomi T., T. Sakamoto, Y. Tokunaga, T. Kameyama, Y. Honda, H. Kamitsuji, I. Kameshita, K. Izumitsu, K. Suzuki, T. Irie

     Current Genetics  61   127 - 140  2015.05

    Joint Work  Joint(The vice charge)

  • MAPKK-encoding gene Ste7 in Bipolaris maydis is required for development and morphogenesis.

    Kitade Y., T. Sumita, K. Izumitsu, C. Tanaka

     Mycoscience  56   150 - 158  2015.03

    Joint Work  Joint(The vice charge)