Cyclophilin A is also known to be recruited by the Gag polyprotein during HIV-1 virus infection, and its incorporation into new virus particles is essential for HIV-1 infectivity.[5]
Cyclophilin D
Cyclophilin D (PPIF, note that literature is confusing, the mitochondrial cyclophilin is encoded by the PPIF gene), which is located in the matrix of mitochondria, is only a modulatory, but may or may not be a structural component of the mitochondrial permeability transition pore.[6][7] The pore opening raises the permeability of the mitochondrial inner membrane, allows influx of cytosolic molecules into the mitochondrial matrix, increases the matrix volume, and disrupts the mitochondrial outer membrane. As a result, the mitochondria fall into a functional disorder, so the opening of the pore plays an important role in cell death. Cyclophilin D is thought to regulate the opening of the pore because cyclosporin A, which binds to CyP-D, inhibits the pore opening.
However, mitochondria obtained from the cysts of Artemia franciscana, do not exhibit the mitochondrial permeability transition pore [8][9]
Clinical significance
Diseases
Overexpression of Cyclophilin A has been linked to poor response to inflammatory diseases, the progression or metastasis of cancer, and aging.[10]
^Menze MA, Hutchinson K, Laborde SM, Hand SC (July 2005). "Mitochondrial permeability transition in the crustacean Artemia franciscana: absence of a calcium-regulated pore in the face of profound calcium storage". Am. J. Physiol. Regul. Integr. Comp. Physiol. 289 (1): R68–76. doi:10.1152/ajpregu.00844.2004. PMID15718386. S2CID8352110.