1. Role of molecular chaperones in the importation of polypeptides into the mitochondrial matrix. Recently synthesized cytoplasmic polypeptides are kept in a loosely folded conformation by cytosolic Hsp70 molecules. In this scheme the polypeptide is represented in the course of translocation through both membranes, and components of the translocation and signal processing machinery other than the chaperones are not shown. As the polypeptide emerges into the matrix it is received by mt-Hsp70 chaperones that apparently pull inward to complete translocation. Dissociation of both the cytoplasmic and matrix chaperones from the polypeptide requires Mg-ATP. Once inside the mitochondrion, the polypeptide is transferred to the mitochondrial tetradecameric chaperonin Hsp60, which completes folding and oligomeric assembly of matrix polypeptides and releases them in a process that requires ATP hydrolysis. OM and IM = outer and inner mitochondrial membranes, respectively; IMS = intermembrane space. (Adapted from Hartl and Martin.17 )
Source: The Biogenesis of Membranes and Organelles, The Online Metabolic and Molecular Bases of Inherited Disease
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular Bases of Inherited Disease; 2014 Available at: Accessed: December 22, 2017
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