Figure 7.

Crosstalk between ER and mitochondria, and MITO protein quality control. TRAP1 forms a supra-molecular complex with TBP7 on the outside of the ER, in a cellular compartment of tight ER–mitochondria contact sites, where proteasomes are also present. This TRAP1/TBP7 complex is involved in the control of protein stability and intracellular protein ubiquitination of mitochondria-destined proteins. These two proteins, each with independent but related functions, help to judge whether a protein can be repaired and reach the final MITO destination or, if damaged, needs to be degraded through the Ub–proteasome system