Prohibitin (PHB)

Prohibitin is a protein which in humans is encoded by the PHB gene. The Phb gene has also been described in animals, fungi, plants and unicellular eukaryotes. Prohibitins are divided in two classes, termed Type-I and Type-II prohibitins, based on their similarity to yeast PHB1 or PHB2, respectively.

Each organism has at least one copy of each type of prohibitin gene.Prohibitins are evolutionarily conserved genes that are ubiquitously expressed. The human prohibitin gene, located on the BRCA1 chromosome region 17q21, was originally thought to be a negative regulator of cell proliferation and a tumor suppressor. This anti-proliferative activity was later attributed to the 3' UTR of the PHB gene, and not to the actual protein.