PROHIBITIN - POTENTIAL ROLE IN SENESCENCE, DEVELOPMENT, AND TUMOR SUPPRESSION

Prohibitin is an evolutionarily conserved gene with homologues found i n organisms ranging from yeast to man. In man the gene is located on c hromosome 17 at q21. The deduced amino acid sequences of the protein p roducts from mouse and rat are identical; and these differ from the hu man protein sequence by a single conserved amino acid. Prohibitin has antiproliferative activity and available data suggest a role in such d iverse processes as normal cell cycle regulation, replicative senescen ce, cellular immortalization, and the development of sporadic breast t umors, Although its functional activity is presently unknown, the 30,0 00-Da protein has been located in the inner membrane of mitochondria, where it is postsynthetically modified, as well as on the plasma membr ane of B cells, where it is associated with the IgM receptor. Prohibit in's evolutionary conservation and ubiquitous expression indicate that it is a fundamentally important gene; and current data suggest a func tional role in such dissimilar processes as development, senescence, a nd tumor suppression.