Does translational control occur in prokaryotes?
Translation in prokaryotes is usually regulated by blocking access to the initiation site. The polycistronic structure of mRNAs is an important aspect of translational control in prokaryotes, but polycistronic mRNAs are not usable (and usually not produced) in eukaryotes.
How is translation controlled in eukaryotes?
Translational control mechanisms are, besides transcriptional control and mRNA stability, the most determining for final protein levels. Cap-dependent translational control occurs mainly during the initiation step, involving eukaryotic initiation factors (eIFs) and accessory proteins.
What causes translational control of gene expression?
mRNA-specific translational control is driven by RNA sequences and/or structures that are commonly located in the untranslated regions of the transcript. These features are usually recognized by regulatory proteins or micro RNAs (miRNAs).
What part of translation is most involved in translational level regulation?
The process of translation can be divided into initiation, elongation, termination, and ribosome recycling. Most regulation is exerted at the first stage, where the AUG start codon is identified and decoded by the methionyl tRNA specialized for initiation (Met-tRNAi).
How does translation occur in prokaryotes?
Prokaryotic transcription and translation can occur simultaneously. This is impossible in eukaryotes, where transcription occurs in a membrane-bound nucleus while translation occurs outside the nucleus in the cytoplasm. Within the nucleus of the cell (light blue), genes (DNA, dark blue) are transcribed into RNA.
Where does translation take place in prokaryotes?
cytoplasm
(a) In prokaryotes, the processes of transcription and translation occur simultaneously in the cytoplasm, allowing for a rapid cellular response to an environmental cue.
How does translation differ in prokaryotes and eukaryotes?
The main difference between prokaryotic and eukaryotic translation is that prokaryotic translation is a simultaneous process with transcription whereas eukaryotic translation is a separate process from its transcription.
What do translational controls regulate?
Translational control governs the efficiency of mRNAs and thus plays an important role in modulating the expression of many genes that respond to endogenous or exogenous signals such as nutrient supply, hormones, or stress. Because the vast majority of eukaryotic mRNAs have quite long half-lives (>2 h) (Raghavan et al.
What is involved in translational regulation?
Translational regulation refers to the control of the levels of protein synthesized from its mRNA. It is affected by many factors such as sex, hormones, cell cycle, growth and development, health status and living environment, as well as the changes of many biochemical substances involved in protein synthesis.
Where does translational regulation take place?
initiation of translation
In most of these cases regulation takes place at the level of initiation of translation, which is often attributable to structural peculiarities of the mRNA in question, especially of the 5′-untranslated region or leader.
Where do transcription and translation take place in prokaryotes?
Prokaryotic transcription occurs in the cytoplasm alongside translation. Prokaryotic transcription and translation can occur simultaneously. This is impossible in eukaryotes, where transcription occurs in a membrane-bound nucleus while translation occurs outside the nucleus in the cytoplasm.
How is translation different in prokaryotes and eukaryotes?
The key difference between eukaryotic and prokaryotic translation is that eukaryotic translation and transcription is an asynchronous process whereas prokaryotic translation and transcription is a synchronous process.