In Fig 11.3 on p 202 of your book, you are shown the various stages at which the
ID: 51994 • Letter: I
Question
In Fig 11.3 on p 202 of your book, you are shown the various stages at which the expression of genes can be regulated. Notice that these different types of gene regulation occur within the nucleus or in the cytoplasm:
Gene Regulation
In general, what is gene regulation and what are the consequences if this process goes awry?
Select two types of regulation (see above for a list); one that occurs in the nucleus and one that occurs in the cytoplasm and briefly explain each process.
Nucleus Cytoplasm Packaging of DNATranscription of a gene
Processing of RNA
Exit of RNA from the nucleus Breakdown of the RNA message
Translation of the mRNA
Modification of the polypeptide
Breakdown of the protein
Explanation / Answer
Gene regulation is the process to control the protein expression in any individual according to the need of body. All genes were not always functional as the the encoded protein by that gene was not always required. So there is a machinary in the body which detects the environmental stimuli and according to the need of bady it controls the processing of protein expression.
Consequences if this process goes awry:
If there is no regulatory process in the body then there may be overexpression or underexpression of proteins and both are very harmful. For example in case of viral infection there is requirement of complementary syatem to be activated which needs some specific proteins for their activation at that time. But it become fetal to our organs if expressed in large amount as they will create autoimmune responces.
Regulation in nucleus:
Transcription of gene: Regulation of transcription is done by transcription factors. These factors bind to a specific site of DNA and either activate or repress the transcription process. These factors work in combination.Factors that activate transcription binds directly or endirectly to the core machinery of trancription through enhancer binding.
Factors that repress tracription causes chromatin condensation of enhancer reagion by deploying co-repressor complexes.
Regulation in Cytoplasm:
Translation of mRNA: Regulation of Translation is mostly accompalished by controllong recruitment of Ribosome to the intiation codon. Sometimes, regulation is done by modulating elongation or termination of protein synthesis.