Communication between mitochondria and chloroplasts at the post-translational level.
(A) The dual-targeted proteins SAL1, PRORS1, and WHIRLY1 have demonstrated roles in organelle retrograde signaling. The dual-targeted protein AT12CYS affects the function of both organelles.
(B) Mitochondria and chloroplasts physically interact through organellar extensions (matrixules and stromules) and glycolytic enzymes. Mitochondria also physically interact with the endoplasmic reticulum (ER) through the mitochondrial contact site and cristae organizing system (MICOS), but how the ER mediates interactions between the MICOS and chloroplasts is still unknown.
(C) Ubiquitin proteasome system regulates functions and biogenesis of mitochondria and chloroplasts by mediating the degradation of protein import machineries.
PRORS1, prolyl-tRNA synthetase 1; UBP27, ubiquitin-specific protease 27; SP1, suppressor of ppi1 locus 1; SPL1, SP1-like 1; GUN 1, genomes uncoupled 1.