title: Mitochondrial protein import and the genesis of steroidogenic mitochondria.
abstract: The principal site of regulation of steroid hormone biosynthesis is the transfer of cholesterol from the outer to inner mitochondrial membrane. Hormonal stimulation of steroidogenic cells promotes this mitochondrial lipid import through a multi-protein complex, termed the transduceosome, spanning the two membranes. The transduceosome complex is assembled from multiple proteins, such as the steroidogenic acute regulatory (STAR) protein and translocator protein (TSPO), and requires their targeting to the mitochondria for transduceosome function. The vast majority of mitochondrial proteins, including those participating in cholesterol import, are encoded in the nucleus. Their subsequent mitochondrial incorporation is performed through a series of protein import machineries located in the outer and inner mitochondrial membranes. Here we review our current knowledge of the mitochondrial cholesterol import machinery of the transduceosome. This is complemented with descriptions of mitochondrial protein import machineries and mechanisms by which these machineries assemble the transduceosome in steroidogenic mitochondria.
authors.affiliation: The Research Institute of the McGill University Health Centre, McGill University, Montreal, Quebec, H3G 1A4, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Midzak
authors.forename: Malena
authors.initials: M
authors.lastname: Rone
authors.forename: Yassaman
authors.initials: Y
authors.lastname: Aghazadeh
authors.forename: Martine
authors.initials: M
authors.lastname: Culty
authors.forename: Vassilios
authors.initials: V
authors.lastname: Papadopoulos
mesh_terms: D000818:Animals; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D013256:Steroids / Q000378:metabolism*
chemical_list: D024101:Mitochondrial Proteins; D013256:Steroids