ReviewRare ER protein misfolding-mistrafficking disorders: Therapeutic developments

- Proteins in order to function need successful processes of transcription, translation, proper folding and trafficking.
- We list and discuss a set of diseases where proteins lose function as they are misfolded due to mutations and as a consequence they are removed by cellular quality control machinery even though they can function if they reach correct destination.
- We highlight the strategies being developed to correct the folding and trafficking defect to restore the protein function.

The presence of a functional protein at the appropriate location in the cell is the result of the processes of transcription, translation, folding and trafficking to the correct destination. There are numerous diseases that are caused by protein misfolding, mainly due to mutations in the respective gene. The consequences of this misfolding may be that proteins effectively lose their function, either by being removed by the cellular quality control machinery or by accumulating at the incorrect intracellular or extracellular location. A number of mutations that lead to protein misfolding and affect trafficking to the final destination, e.g. Cystic fibrosis, Wilson's disease, and Progressive Familial Intrahepatic 1 cholestasis, result in proteins that retain partial function if their folding and trafficking is restored either by molecular or pharmacological means. In this review, we discuss several mutant proteins within this class of misfolding diseases and provide an update on the status of molecular and therapeutic developments and potential therapeutic strategies being developed to counter these diseases.