9.B.317.  The Complex I Integral Membrane Chaperone, TMEM126 (TMEM126) Family 

Cell stress such as hypoxia elicits adaptive responses on cells. An assembly factor for mitochondrial complex I is transmembrane protein 126B (TMEM126B). Fuhrmann et al. 2018 identified changes in complex I abundance under chronic hypoxia, in association with impaired substrate-specific mitochondrial respiration. Complexome profiling of isolated mitochondria of the human leukemia monocytic cell line THP-1 revealed deficits in complex I assembly. They demonstrated a selective decrease of TMEM126B under chronic hypoxiadue to the proteolytic degradation of TMEM126B.


 

References:

Fuhrmann, D.C., I. Wittig, S. Dröse, T. Schmid, N. Dehne, and B. Brüne. (2018). Degradation of the mitochondrial complex I assembly factor TMEM126B under chronic hypoxia. Cell Mol Life Sci 75: 3051-3067.
Kloth, K., M. Synofzik, C. Kernstock, S. Schimpf-Linzenbold, F. Schuettauf, A. Neu, B. Wissinger, and N. Weisschuh. (2019). Novel likely pathogenic variants in TMEM126A identified in non-syndromic autosomal recessive optic atrophy: two case reports. BMC Med Genet 20: 62.
Examples:

TC#NameOrganismal TypeExample
9.B.317.1.1

TMEM126B chaparone protein for Miltochondrial Complex I of 230 aas and 4 TMSs. See the family description for details (Fuhrmann et al. 2018).

TM126 of Homo sapiens

 
9.B.317.1.2

TMEM126A of 195 aas and 4 TMSs.  This protein shows distant similarity to members of the mitochondrial carrier (MC) Family (2.A.29), but homology has not been established. Pathogenic splice variants have been detected that give rise to non-syndromic autosomal recessive optic atrophy (Kloth et al. 2019).

TMEM126A of Homo sapiens

 
9.B.317.1.3

Uncharacterized protein, DmeI, of 223 aas and 4 TMSs.

UP of Drosophila melanogaster (Fruit fly)

 
9.B.317.1.4

Uncharacterized protein of 202 aas and 4 TMSs.

UP of Echinococcus granulosus (Hydatid tapeworm)

 
9.B.317.1.5

Uncharacterized protein of 236 aas and 4 TMSs.

UP of Brachionus plicatilis

 
9.B.317.1.6

Uncharacterized putative tRNA-specific adenosine deaminase-like protein 3 of 671 aas and 4 N-terminal TMSs homologous to TMEM126.

UP of Clonorchis sinensis

 
Examples:

TC#NameOrganismal TypeExample
9.B.317.2.1

Uncharacterized protein of 274 aas and 4 TMSs.

UP of Trichuris trichiura

 
9.B.317.2.2

Uncharacterized protein of 306 aas and 4 TMSs.

UP of Ancylostoma caninum (dog hookworm)