Possible existence of lysosome-like organelle within mitochondria and its role in mitochondrial quality control

2014 Fiscal Year Final Research Report

• Project/Area Number: 25670169
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Pathological medical chemistry
• Research Institution: National Cancer Center Japan
• Principal Investigator: ARAKAWA Hirofumi 独立行政法人国立がん研究センター, 研究所, 分野長 (70313088)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: リソソーム / ミトコンドリア / タンパク質分解 / オートファジー / 活性酸素種 / 酸化ストレス / 酸化タンパク質 / 品質管理機構

Outline of Final Research Achievements

In the present study, by performing electron microscopic and immune-electron microscopic analyses and protenase K protection assay, we confirmed that at least four lysosomal proteins (Cathepsin-B, Cathepsin-D, LAMP1 and LAMP2) are accumulated within mitochondria without destroying the mitochondrial structure in response to hypoxia in mouse embryonic fibroblasts and human normal mammary epithelial cells. Therefore, the Mieap-induced accumulation of lysosome-like organelles within mitochondria is a hypoxic-responsive physiological function in the cell, which is conserved at least from mouse to human.

Free Research Field

腫瘍生物学