Role of prohibitins in the mitochondrial inner membrane

Prohibitins comprise a highly conserved and ubiquitously expressed protein family in eukaryotic cells which have been linked to diverse processes, such as cellular signalling and transcriptional control, the regulation of cell proliferation, apoptotic and developmental processes, and to the biogenesis of mitochondria. The function of prohibitins on the molecular level, however, is currently not understood and in the focus of our research. Single particle analysis of isolated yeast prohibitin complexes revealed ring-like complexes with a diameter of 20-25 nm composed of two highly homologous subunits which may provide a scaffold for protein organization within the inner membrane of mitochondria. Prohibitins interact with an AAA protease and therefore are functionally linked to proteolytic processes in the membrane. We are analysing their function using genome-wide genetic screening procedures in yeast and murine models allowing the inactivation of prohibitin complexes.

 

EM single particle analysis of an individual prohibitin complexes of S. cerevisiae. Bar 20 nm.

Prohibitins assemble with mAAA proteases into supercomplexes in the mitochondrial inner membrane.