TY  - JOUR
A1  - Babot, Marion
A1  - Labarbuta, Paola
A1  - Birch, Amanda
A1  - Kee, Sara
A1  - Fuszard, Matthew
A1  - Botting, Catherine H.
A1  - Wittig, Ilka
A1  - Heide, Heinrich
A1  - Galkin, Alexander
T1  - ND3, ND1 and 39kDa subunits are more exposed in the de-active form of bovine mitochondrial complex I
T2  - Biochimica et biophysica acta
N2  - An intriguing feature of mitochondrial complex I from several species is the so-called A/D transition, whereby the idle enzyme spontaneously converts from the active (A) form to the de-active (D) form. The A/D transition plays an important role in tissue response to the lack of oxygen and hypoxic deactivation of the enzyme is one of the key regulatory events that occur in mitochondria during ischaemia. We demonstrate for the first time that the A/D conformational change of complex I does not affect the macromolecular organisation of supercomplexes in vitro as revealed by two types of native electrophoresis. Cysteine 39 of the mitochondrially-encoded ND3 subunit is known to become exposed upon de-activation. Here we show that even if complex I is a constituent of the I+III2+IV (S1) supercomplex, cysteine 39 is accessible for chemical modification in only the D-form. Using lysine-specific fluorescent labelling and a DIGE-like approach we further identified two new subunits involved in structural rearrangements during the A/D transition: ND1 (MT-ND1) and 39kDa (NDUFA9). These results clearly show that structural rearrangements during de-activation of complex I include several subunits located at the junction between hydrophilic and hydrophobic domains, in the region of the quinone binding site. De-activation of mitochondrial complex I results in concerted structural rearrangement of membrane subunits which leads to the disruption of the sealed quinone chamber required for catalytic turnover.
KW  - A/D transition
KW  - Complex I
KW  - Conformational change
KW  - N-hydroxysuccinimide
KW  - NADH:ubiquinone oxidoreductase
KW  - Protein tyrosine modification
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/34554
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-345543
SN  - 1879-2650
SN  - 0005-2728
N1  - Open Access funded by Medical Research Council. Under a Creative Commons license: http://creativecommons.org/licenses/by/3.0/
VL  - 1837
IS  - 6
SP  - 929
EP  - 939
PB  - Elsevier
CY  - Amsterdam
ER  -