Marine-derived microbes and molecules for drug discovery.

Increasing attention has been paid to marine-derived biomolecules as sources of therapeutics for autoimmune diseases. Nagasaki Prefecture has many islands and is surrounded by seas, straits, gulfs, bays, and coves, giving it the second longest coastline in Japan after Hokkaido. We have collected more than 20,000 marine microbes and have been preparing an original marine microbial extract library, which contains small and mid-size biomolecules that may penetrate cell membranes and interfere with the intracellular protein-protein interaction involved in the development of autoinflammatory diseases such as familial Mediterranean fever.

Cleaved PGAM5 dephosphorylates nuclear serine/arginine-rich proteins during mitophagy.

PGAM5 is a protein phosphatase located in the inner mitochondrial membrane through its transmembrane (TM) domain and is cleaved within the TM domain upon mitochondrial dysfunction. We found previously that cleaved PGAM5 is released from mitochondria, following proteasome-mediated rupture of the outer mitochondrial membrane during mitophagy, a selective form of autophagy specific to mitochondria. Here, we examined the role of cleaved PGAM5 outside mitochondria.