Integrative Life Sciences :
Cellular Network


Organelle Pathophysiology

Organelle Pathophysiology

Eukaryotic cells have a number of intracellular organelles with distinct functions. Interestingly enough, these organelles never function alone; they cooperatively regulate cellular homeostasis, proliferation, and differentiation, through a continuous exchange of soluble and membrane-bound molecules via membrane trafficking and/or membrane contact transfer. A failure in organelle cooperation often results in various human diseases. Our laboratory uses methods in biochemistry, cell biology, and molecular biology to identify novel organellar proteins and lipids. With these methods, we aim to unveil novel functions of organelles and the molecular mechanisms that regulate organelle cooperation. We especially focus on molecules that reside on the cytoplasmic face of the organelles; the essential face that physically interacts with other organelles and cytosol. Our results will help develop new treatments for diseases such as cancer and autoinflammatory diseases that are caused by disrupted organelle cooperation.

Research Overview

Intracellular organelles have unique membrane lipid compositions. This feature endows organelles with their specific functions. For example, we have shown that (1) recycling endosomes are enriched in phosphatidylserine, a class of glycerophospholipids, and regulate membrane trafficking and cellular proliferation through a variety of phosphatidylserine-binding proteins: (2) the Golgi complex is enriched in sphingomyelin, a class of sphingolipids, and functions in triggering the innate immunity signaling pathway against cytosolic DNA viruses.
    Recently we have developed a novel method to identify organelle resident proteins using specific probes for organelle membrane phospholipids. This method is highly expected to reveal "unforeseen" function of intracellular organelles.

Faculty Members

Professor TAGUCHI Tomohiko
Assistant Professor MUKAI Kojiro