Analysis of the novel dense granule protein in Toxoplasma gondii

• Project/Area Number: 25850197
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Veterinary medical science
• Research Institution: Chubu University (2015); Obihiro University of Agriculture and Veterinary Medicine (2013-2014)
• Principal Investigator: OKADA Tadashi 中部大学, 生命健康科学部, 研究員 (30623855)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: トキソプラズマ原虫 / dense granule protein / egress / エグレス

Outline of Final Research Achievements

The intracellular protozoan parasite Toxoplasma gondii is capable of invading any nucleated cell and replicates within a parasitophorous vacuole (PV). This microenvironment is modified by secretory proteins from organelles named rhoptries and dense granules. In this study, we identified the novel dense granule protein in Toxoplasma gondii. To understand the novel dense granule protein function, we performed disruption of this gene by homologous recombination, and analyzed its phenotypes.
The knock out strain showed similar growth rate as that of parental strain. The survival rate did not show significant difference between mice infected with knock out and parental strains. However, timing of egress was earlier than that of parental strain. These results suggested that this novel dense granule protein involved in regulating the parasite egress in T. gondii.

Research Products

• [Journal Article] Seroprevalences of <i>Toxoplasma gondii</i> and <i>Neospora caninum</i> in Pet Rabbits in Japan (2014)
  • Author(s): Salman, D., Oohashi, E., Mohamed, A.E.E., El-Mottelib, A.E.A., Okada, T., Igarashi, M.
  • Journal Title: Journal of Veterinary Medical Science Volume: 76 Issue: 6 Pages: 855-862
  • DOI: 10.1292/jvms.13-0632
  • NAID: 130003391296
  • ISSN: 0916-7250, 1347-7439
  • Peer Reviewed / Open Access
• [Journal Article] A novel dense granule protein, GRA22, is involved in regulating parasite egress in Toxoplasma gondii. (2013)
  • Author(s): Okada T, Marmansari D, Li ZM, Adilbish A, Canko S, Ueno A, Shono H, Furuoka H, Igarashi M.
  • Journal Title: Mol Biochem Parasitol. Volume: 189 Issue: 1-2 Pages: 5-13
  • DOI: 10.1016/j.molbiopara.2013.04.005
  • Peer Reviewed
• [Presentation] トキソプラズマGRA22は宿主からの脱出時機制御機構に関与する (2013)
  • Author(s): 岡田只士, Compaore M, Marmansari D, Li ZM, Adilbish A, Canko S, 上野晃生, 五十嵐慎
  • Organizer: 第156回日本獣医学会学術集会
  • Place of Presentation: 岐阜大学（岐阜市）
• [Presentation] トキソプラズマGRA22の宿主細胞からの脱出時機制御機構への関与 (2013)
  • Author(s): 岡田只士, Compaore M, Marmansari D, Li ZM, Adilbish A, Canko S, 上野晃生, 五十嵐慎
  • Organizer: 第36回日本分子生物学会年会
  • Place of Presentation: 神戸ポートアイランド（神戸市）