Translocation of mitochondrial inner-membrane proteins: conformation matters

TY - JOUR

T1 - Translocation of mitochondrial inner-membrane proteins

T2 - conformation matters

AU - de Marcos-Lousa, Carine

AU - Sideris, Dionisia P.

AU - Tokatlidis, Kostas

N1 - Funding Information: Supported by IMBB-FORTH funds, the University of Crete, the UK Medical Research Council, and the European Social Fund and National resources. C. dM-L. is a FEBS postdoctoral fellow, and D.P.S. was supported by a PENED grant from the Greek General Secretariat of Research and Technology. Copyright: © 2006 Elsevier Ltd. All rights reserved.

PY - 2006/5

Y1 - 2006/5

N2 - Most of the mitochondrial inner-membrane proteins are generated without a presequence and their targeting depends on inadequately defined internal segments. Despite the numerous components of the import machinery identified by proteomics, the properties of hydrophobic import substrates remain poorly understood. Recent studies support several principles for these membrane proteins: first, they become organized into partially assembled forms within the translocon; second, they present noncontiguous targeting signals; and third, they induce conformational changes in translocase subunits, thereby mediating 'assembly on demand' of the import machinery. It is possible that the energy needed for these proteins to pass across the outer membrane, to travel through the intermembrane space and to target the inner-membrane surface is provided by conformational changes involving import components that seem to have natively unfolded structures. Such structural malleability might render some of the translocase subunits more adept at driving the protein import process.

AB - Most of the mitochondrial inner-membrane proteins are generated without a presequence and their targeting depends on inadequately defined internal segments. Despite the numerous components of the import machinery identified by proteomics, the properties of hydrophobic import substrates remain poorly understood. Recent studies support several principles for these membrane proteins: first, they become organized into partially assembled forms within the translocon; second, they present noncontiguous targeting signals; and third, they induce conformational changes in translocase subunits, thereby mediating 'assembly on demand' of the import machinery. It is possible that the energy needed for these proteins to pass across the outer membrane, to travel through the intermembrane space and to target the inner-membrane surface is provided by conformational changes involving import components that seem to have natively unfolded structures. Such structural malleability might render some of the translocase subunits more adept at driving the protein import process.

UR - https://www.scopus.com/pages/publications/33646354157

U2 - 10.1016/j.tibs.2006.03.006

DO - 10.1016/j.tibs.2006.03.006

M3 - Article

C2 - 16616497

AN - SCOPUS:33646354157

SN - 0968-0004

VL - 31

SP - 259

EP - 267

JO - Trends in Biochemical Sciences

JF - Trends in Biochemical Sciences

IS - 5

ER -