OPA1 belongs to the Dynamin large GTPase protein family. OPA1 exists as a single-pass membrane protein localized in the mitochondrial inner membrane and also as a soluble form in the mitochondrial intermembrane space. There, it is a key player in fusion of the inner mitochondrial membrane as well as maintenance of the cristae architecture. The oligomerization of differentially processed forms of OPA1 directs mitochondrial membrane formation.
xCT is an obligate, electroneutral, membrane-bound anionic transporter responsible for regulating particular amino acid gradients via their transport through plasma membrane. The antiporter xCT superficially resembles an ion channel and preferentially catalyzes the exchange of L-cystine for L-glutamate residues in animal cells. Unlike other glutamate transporters like EAATs, xCT functions independently of an electrochemical sodium ion gradient. xCT is present in most peripheral tissues (heart, bone, liver, and testes).
ABCA1 is a key gatekeeper influencing intracellular cholesterol transport, and is an important member of a multifamily of cAMP-dependent anion transporter cell membrane proteins that regulate reverse cholesterol efflux from cells in peripheral tissues to apolipoprotein A1. ABCA1 has a wide expression profile with highest expression levels found in macrophages.