Hiromi Sesaki

Hiromi Sesaki, Ph.D.


410-502-6842 (Office), 410-955-4129 (Fax)

Department of Cell Biology
Johns Hopkins University School of Medicine
725 N. Wolfe Street, 119 Hunterian
Baltimore, MD 21205

Academic Titles


Research Topic

Mitochondrial dynamics; membrane fusion and fission

Research Topic:  Mitochondrial Dynamics and Phospholipid Metabolism

Our laboratory is interested in the molecular mechanisms and physiological roles of mitochondrial fusion. Mitochondria are highly dynamic and control their morphology by a balance of fusion and fission. The regulation of membrane fusion and fission generates a striking diversity of mitochondrial shapes, ranging from numerous small spheres in hepatocytes to long branched tubules in myotubes. In addition to shape and number, mitochondrial fusion is critical for normal organelle function. For example, mice that are defective in mitochondrial fusion die during early development while yeast fusion mutants rapidly lose their mitochondria genome and become incapable of oxidative phosphorylation. Moreover, mitochondrial fusion also regulates the release of cytochrome C during apoptosis. Therefore, it is not surprising that defects in mitochondrial fusion cause neurodegenerative disorders in humans, including Charcot-Marie-Tooth disease type 2A and autosomal dominant optic atrophy.

Using yeast as a model system, we have identified several components that mediate and regulate mitochondrial fusion. We are currently trying to determine their functions in both yeast and mammals. The goals of our research are to understand the molecular basis of mitochondria fusion using biochemical approaches and to determine the physiological roles of mitochondrial fusion using cell culture and animal models.