Question

In stressful conditions, a cell wants to limit expression of Protein X. List all the ways that this can occur.

Answer 1

Proteins are the functional components of the cells. However, the proteins are tightly regulated to ensure homeostasis.

There are several levels at which the protein expression can be limited:

1. Turning down the transcription of the gene that encodes the protein so that the level of the transcripts is low and hence the level of proteins would be also low. Thus, by reducing the expression of the gene, the protein levels can be regulated.

2. Degrading of the mRNA transcripts is another way of decreasing the levels of proteins. This is done by RNAi silencing and direct degradation of mRNA.

3. Lowering the translation of the protein is another mechanism where the RNA is silenced thereby even if the transcripts are present they are not translated or translated at lower levels.

4. Degradation of the proteins by the systems like proteasome and chaperone-mediated degradation result in the lowering of the protein levels.