Functional analysis of a novel posttranslational modification factor UBL3 as the protein sorting machinery in exosomes

• Project/Area Number: 26640084
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Tumor biology
• Research Institution: Fujita Health University
• Principal Investigator: Ageta Hiroshi 藤田保健衛生大学, 総合医科学研究所, 助教 (40416649)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2014: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: Ubiquitin / 翻訳後修飾 / UBL3 / ユビキチン様タンパク質

Outline of Final Research Achievements

We here used bioinformatics techniques to identify a novel protein, ubiquitin-like protein 3 (UBL3), as a membrane-localized, highly conserved ubiquitin domain-containing protein. We found that UBL3 acts as a novel posttranslational modification factor. Furthermore, we showed that UBL3 is specifically colocalized with exosome marker proteins and is released in cell culture medium. When fused with UBL3, enhanced green fluorescent protein (EGFP), mCherry and biotinylated tag are all sorted to exosomes. The total protein levels in serum exosomes purified from UBL3 KO mice were 60% lower than those in exosomes purified from wild-type mice. However, we did not find any significant differences in the levels of miRNAs such as miR-16, miR-23, and miR-21. The concentration of exosome particles and the average particle diameter in the serum exosome did not differ between the UBL3 KO and wild-type mice. These results indicate that UBL3 selectively influences the sorting of proteins to exosomes.

Research Products

• [Presentation] New biomarkers of osteoarthritis (2016)
  • Author(s): Takashi Kuroiwa, Hiroshi Ageta, Daiki Ikeda, Mitsuhiro Morita, Kunihiro Tsuchida, Harumoto Yamada
  • Organizer: Osteoarthitis Research Society International (OARSI)
  • Place of Presentation: オランダ
  • Year and Date: 2016-03-31
• [Presentation] 変形性関節症の新規バイオマーカー (2016)
  • Author(s): 黒岩宇, 上田洋司, 土田邦博, 山田治基
  • Organizer: 第29回日本軟骨代謝学会
  • Place of Presentation: 広島
  • Year and Date: 2016-02-19
• [Presentation] Establishment of an in vivo exosomal transfection as a new gene therapy (2015)
  • Author(s): Hiroshi Ageta, Keisuke Hitachi, Masashi Nakatani, Kunihiro Tsuchida
  • Organizer: 国際細胞外小胞学会(ISEV)
  • Place of Presentation: ワシントンDC
  • Year and Date: 2015-04-23
• [Book] The role of myostatin and related factors in muscle hypertrophy and atrophy (2016)
  • Author(s): Kunihiro Tsuchida, Keisuke Hitachi, Masashi Nakatani, Akiyoshi Uezumi, Hiroshi Ageta
  • Total Pages: 200
  • Publisher: Nova Science publishers