Coassembly of Mgm1 isoforms requires cardiolipin and mediates mitochondrial inner membrane fusion

The soluble and membrane-anchored isoforms of Mgm1 are only active when they work together (in trans)

Mechanisms bywhich dietary fatty acids regulate mitochondrial structure-function in health and disease

Mitochondria are the energy-producing organelles within a cell. Furthermore, mitochondria have a role in maintaining cellular homeostasis and proper calcium concentrations, building critical components of hormones and other signaling molecules, and controlling apoptosis. Structurally, mitochondria are unique because they have 2 membranes that allow for compartmentalization. The composition and molecular organization of thesemembranes are crucial to the maintenance and function of mitochondria. In this review, we first present a general overview of mitochondrial membrane biochemistry and biophysics followed by the role of different dietary saturated and unsaturated fatty acids in modulatingmitochondrial membrane structure-function.We focus extensively on long-chain n-3 (ω-3) polyunsaturated fatty acids and their underlyingmechanisms of action. Finally,we discuss implications of understanding molecular mechanisms by which dietary n-3 fatty acids targetmitochondrial structure-function in metabolic diseases such as obesity, cardiac-ischemia reperfusion injury, obesity, type 2 diabetes, nonalcoholic fatty liver disease, and select cancers

Identification of mitochondrial and microsomal phosphatidylserine synthase in Saccharomyces cerevisiae as the gene product of the CHO1 structural gene.

In Saccharomyces cerevisiae, the membrane-associated enzyme phosphatidylserine synthase (EC 2.7.8.8) is present in the mitochondria and the endoplasmic reticulum. The enzyme from both membrane fractions reacted with antiserum raised against a hybrid protein expressed from a TRPE-CHO1 fusion gene in Escherichia coli and was absent in a cho1 null mutant, strongly suggesting that both the mitochondrial and microsomal forms of phosphatidylserine synthase are the products of the CHO1 gene. The highest degree of purification of enzymatically active protein was 380- and 420-fold from the mitochondrial and the microsomal compartments, respectively. In both cases, the enzymatically active and immunoreactive material comigrated with a protein band of 30,000 apparent molecular weight. In the absence of protease inhibitors during the preparation of membranes, the enzyme underwent degradation to an enzymatically active protein of 23,000 apparent molecular weight

Phospholipid asymmetry of the outer membrane of rat liver mitochondria : evidence for the presence of cardiolipin on the outside of the outer membrane

The phospholipid topology of the outer membrane of intact rat liver mitochondria and derived outer membrane vesicles was investigated by determining the accessible pool of the various phospholipid classes towards phospholipase A2, a phosphatidylcholine-specific transfer protein and by chemical labeling using trinitrobenzene sulfonic acid. The outer membrane vesicles are sealed and have a right-side-out topology with a proposed localization of 55%, 77%, 100%, and at least 30% of the phosphatidylcholine, phosphatidylethanolamine, cardiolipin, and phosphatidylinositol plus phosphatidylserine in the outer leaflet, respectively. The outer membrane in intact mitochondria appears to have a similar phospholipid distribution