short notes on these topics about 1 1/2 pages
a) Nuclear export of mRNA
b) mRNA stability
c) Inhibitors of transcription and their mode of action
d) Inhibitors of translation and their mode of action
Nuclear Export of mRNA
The expression of eukaryotic genes is controlled by several mechanisms. Its regulation is considered to be critical for physiological responses associated with intracellular and extracellular signals. One of the most critical steps in eukaryotic gene expression is the messenger RNA transcripts' movement, which is commonly presented as mRNA. The mRNA usually moves to the cytoplasm from the nucleus, where it is synthesized during the eukaryotic gene expression. In the cytoplasm, the mRNA is usually translated to protein. The mRNA nuclear export transcripts can be divided into two different stages. The first stage involves transcription of the pre-mRNA in the nucleus, which is its site for processing and packaging to form messenger ribonucleoproteins(RNPs), which are complex. The second stage involves targeting and translocation via nuclear pore complexes. In the third stage, the mRNPs tend to be directionally released to move to the cytoplasm where it is translated.
Gene expression regulation is critical for an organism's homeostasis. It plays a great role in the proliferation and differentiation of a cell and responds to a given stimulus. Research conducted over20 years ago has indicated that mRNA modulation plays a great role in gene expression stability. In this case, the mRNA stability transcript varies depending on the mRNA sequences referred to as cis-elements. The cis-elements are bound RNA-binding trans-acting proteins to enhance or inhibit RNA decay.
Inhibitors of Transcription
The transcription inhibitor that is most commonly used is the DRB. These initials stand for 5,6-Dichloro-1-beta-Ribo-furanosyl Benzimidazole. The compound was previously considered to serve as a nuclear heterogeneous RNA inhibitor synthesis. However, it was reported to contribute to the formation of premature chain termination. The major component of this compound is considered to be the CDK9. However, the compound serves as an inhibitor for the CDK7, which is a TFIIH kinase subunit that displays a 3-fold lower efficiency. The component is usually applied with a concentration that is almost equal to its maximal solubility.
Inhibitors of Translation
There are several known eukaryotic translation inhibitors. However, one of the most commonly known translation inhibitors is CHX,1, which is the initials of cycloheximide. Cycloheximide is considered to be the most commonly applied laboratory reagents during the inhibition of protein synthesis. CHX has severally been found to inhibit the eukaryotic translation elongation phase. In this case, it takes part in the binding of the ribosome and blocks eEF-mediated translocation.