Coiled Coil Helix Coiled Coil Helix Domain Containing Protein 3 (CHCHD3)

ChChd3 contains a myristylation motif followed by DUF domain and a CHCH domain. In mouse fibroblasts, the endogenous ChChd3 is primarily localized to mitochondria, sometimes also seen in nucleus. However, over-expressed ChChd3 is localized only to mitochondria. Deletion of CHCH domain disrupts mitochondrial localization suggesting that CHCH domain is an essential targeting motif in ChChd3. In vitro protein import studies showed that in addition to cysteines in CHCH domain, myristoylation is also necessary for targeting the protein to the IM of mitochondria. Over-expressed ChChd3 in HEK 293 cells binds to PKA and shows a clear increase in phosphorylation at Thr10 upon stimulation with 8-CPT cAMP.