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Abl2 kinase phosphorylates Bi-organellar regulator MNRR1 in mitochondria, stimulating respiration

We previously showed that MNRR1 (Mitochondrial Nuclear Retrograde Regulator 1, also CHCHD2) functions in two subcellular compartments, displaying a different function in each. In the mitochondria it is a stress regulator of respiration that binds to cytochrome c oxidase (COX) whereas in the nucleus it is a transactivator of COX4I2 and other hypoxia-stimulated genes. We now show that binding of MNRR1 to COX is promoted by phosphorylation at tyrosine-99 and that this interaction stimulates respiration. We show that phosphorylation of MNRR1 takes place in mitochondria and is mediated by Abl2 kinase (ARG). A family with Charcot-Marie-Tooth disease type 1A with an exaggerated phenotype harbors a Q112H mutation in MNRR1, located in a domain that is necessary for transcriptional activation by MNRR1. Furthermore, the mutation causes the protein to function suboptimally in the mitochondria in response to cellular stress. The Q112H mutation hinders the ability of the protein to interact with Abl kinase, leading to defective tyrosine phosphorylation and a resultant defect in respiration.

Related Products

Cat.No. Product Name Information Publications Customer Product Validation
S7565 WH-4-023 WH-4-023 is a potent and orally active Lck/Src inhibitor with IC50s of 2 nM and 6 nM in cell-free assays, respectively. Exhibits >300-fold selectivity against p38α and KDR. Also potently inhibits SIK (IC50 values are 10, 22 and 60 nM for SIK 1, 2 and 3 respectively) and displays selectivity over a range of closely related kinases. (3) (1)

Related Targets

Src