The Mitochondrial Permeability Transition Pore: Molecular Structure and Function in Health and Disease

Ion transport across the mitochondrial inner and outer membranes is central to mitochondrial function, including regulation of oxidative phosphorylation and cell death. Although required for ATP production by mitochondria, recent findings have confirmed that the c-subunit of the ATP synthase also houses a large conductance uncoupling channel, the mitochondrial permeability transition pore (mPTP), the persistent opening of which produces osmotic dysregulation of the inner mitochondrial membrane and cell death. This chapter will discuss recent advances in understanding the molecular components of mPTP, its regulatory mechanisms during cell death, and its function in diseases of the brain. In contrast to mitochondrial inner membrane uncoupling, enhanced coupling occurs in states of improved mitochondrial efficiency; relative closure of mPTP therefore contributes to cell functions as diverse as cardiac development and synaptic efficacy.