Chaperones assist protein folding
doi:10.1038/nindia.2012.4 Published online 18 January 2012
Researchers have found that chemical chaperones assist in protein folding (a process through which proteins attain their shape and conformation) inside living cells thereby helping silence a significant number of genetic mutations.
There are large genetic differences between individuals in a population. However, most of these mutations are silent. A significant fraction of these are believed to be silenced by active mechanisms collectively called 'genetic buffering'.
A potential source of problems in protein folding is change in the genetic code that leads to altered amino acid sequences. It is believed that folding machinery of the cell plays an active role in buffering mutations in the coding region.
The researchers tried to find if the chemical environment of the cell can change folding pathways and thereby buffer mutations.
Using model proteins to study protein folding, they showed that chemical chaperones are able to assist protein folding in vivo. Interestingly, different chemical chaperones helped different mutations reach the native state.
Chemical composition of a cell can contribute to its folding capacity, the researchers contend. "This implies that the chemical milieu of a cell may also contribute to the buffering capacity of an organism by assisting different mutant proteins in reaching their native state," says one of the researchers Kausik Chakraborty.
Further experiments will prove if misfolding defects are associated with osmolyte imbalance that alters the folding capacity of a cell, he adds.
- Bandyopadhyay, A. et al. Chemical chaperones assist intracellular folding to buffer mutational variations. Nat. Chem. Biol. doi: 10.1038/nchembio.768 (2011)