Question

Name and describe one method a eukaryotic cell can regulate transcription of a gene

Name and describe one method a eukaryotic cell can regulate translation of a gene

Name and describe one method a eukaryotic cell can regulate expression of a gene at any level

Answer 1

REGULATION OF OF TRANCRIPTRANS IN EUKARYOTES

METHYLATION OF DNA is a mechanism of regulation of transcription in eukaryotes that vertebrates is linked to chromatin structure. Cytosine residues in vertebrate DNA can be modified by the addition of methyl groups at the 5-carbon position .DNA is methylated specifically at the C's that precede G's in the DNA chain. This methylation is correlated with reduced transcriptional activity of genes that contain high frequencies of CpG dinucleotides in the vicinity of their promoters. Methylation inhibits transcription of these genes via the action of a protein, MeCP2, that specifically binds to methylated DNA and represses transcription. Interestingly, MeCP2 functions as a complex with histone deacetylase, linking DNA methylation to alterations in histone acetylation and nucleosome structure

DNA METHYLATION

Then in the case of prokaryotes,TRANSLATIONAL CONTROL VIA CAP RECOGNITION PROCESS

A mechanism in eukaryotes to control the rate of translation initiation involves the mRNA 5′-cap recognition process by eIF4F. Binding of eIF4F to the cap structure can be hindered by the eIF4E homolog, 4E-HP .The interaction between eIF4G and eIF4E in the eIF4F complex is inhibited by members of a family of related proteins, termed eIF4E-binding proteins.The 4E-BPs compete with eIF4G for a shared binding site on eIF4E. Consequently, 4E-BPs inhibit cap-dependent, but not IRES-dependent, translation. 4E-BP binding to eIF4E is controlled by phosphorylation. Hypo-phosphorylated 4E-BPs bind strongly to eIF4E, whereas phosphorylation of 4E-BPs weakens their interaction with eIF4E .

Eukaryotic gene expression involves many steps, and almost all of them can be regulated. Different genes are regulated at different points, and it’s not uncommon for a gene to be regulated at multiple steps.

One of the step is chromatin accessibility.

• Chromatin accessibility. The structure of chromatin DNA and its organizing proteins) can be regulated. More open or “relaxed” chromatin makes a gene more available for transcription.