ASSOCIATION OF RHO PROTEINS WITH THE MITOCHONDRIA ORGANELLE

The proteins of the rho gene family have been isolated from cytosolic as well as particulate fractions. The rho proteins have values of abou t 22KDa and have consensus amino acid sequences for GTP/GDP-binding an d GTPase activities. We have localized the rho proteins in mammalian c ells by using affinity-purified anti-peptide antibodies in immunofluor escence and immunoelectron microscopy studies. The majority of rho app ears to be concentrated in the mitochondrial membranes while a small f raction is seen in the cytoplasm and in the cytosolic lysosomal compar tments, suggesting that rho protein(s) might be involved in the mitoch ondrial function or assembly.