This report describes the cloning and characterization of a plant cDNA coding for a protein which shows high amino acid sequence similarity with prohibitin, whose gene is associated with antiproliferative activity in mammalian cells. Arabidopsis thaliana and Nicotiana tabacum prohibitin complete cDNAs were isolated, and the expression pattern of prohibitin was examined using polyclonal antibodies raised against the Arabidopsis recombinant prohibitin expressed in Escherichia coli. A single immunoreactive protein was detected in various plant species and in all Arabidopsis organs examined. Subcellular fractionation using tobacco leaves revealed prohibitin in a mitochondrial-enriched fraction. Phylogenetic conservation of prohibitin's amino acid sequence and subcellular localization suggests a similar function in plants, yeast and mammals.