Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Initiation of Translation02:33

Initiation of Translation

32.3K
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
32.3K
Improving Translational Accuracy02:07

Improving Translational Accuracy

9.9K
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
9.9K
Leaky Scanning02:28

Leaky Scanning

5.1K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA.  Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.1K
Transcription Elongation Factors02:35

Transcription Elongation Factors

10.8K
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA...
10.8K
Regulated mRNA Transport02:22

Regulated mRNA Transport

6.3K
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing...
6.3K
Termination of Translation01:44

Termination of Translation

25.3K
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
25.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Remodeling of mRNA by eIF4F in human translation initiation.

bioRxiv : the preprint server for biology·2026
Same author

A ribosomal kinetic checkpoint governs selective mRNA recruitment.

bioRxiv : the preprint server for biology·2026
Same author

Harnessing viral strategies to reverse cognitive dysfunction through the integrated stress response.

Science (New York, N.Y.)·2026
Same author

Massive Bilateral Pulmonary Thromboembolism Due to a Thrombus in Transit to the Right Atrium: A Case Report.

Cureus·2026
Same author

Combined inhibition of polyamine biosynthesis and uptake blocks <i>Candida albicans</i> virulence.

mBio·2025
Same author

Conserved +1 translational frameshifting in the Saccharomyces cerevisiae gene encoding YPL034W.

The Journal of biological chemistry·2025

Related Experiment Video

Updated: Jun 20, 2025

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
10:37

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs

Published on: May 10, 2018

12.5K

eIF1 and eIF5 dynamically control translation start site fidelity.

Rosslyn Grosely1, Carlos Alvarado1, Ivaylo P Ivanov2

  • 1Dept. of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.

Biorxiv : the Preprint Server for Biology
|July 19, 2024
PubMed
Summary
This summary is machine-generated.

Eukaryotic initiation factors eIF1 and eIF5 coordinate protein synthesis start site selection. Their distinct binding dynamics ensure accurate translation initiation, preventing errors in protein identity and function.

More Related Videos

Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells
08:47

Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells

Published on: May 1, 2020

3.1K
Xenopus laevis as a Model to Identify Translation Impairment
10:24

Xenopus laevis as a Model to Identify Translation Impairment

Published on: September 27, 2015

10.7K

Related Experiment Videos

Last Updated: Jun 20, 2025

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
10:37

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs

Published on: May 10, 2018

12.5K
Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells
08:47

Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells

Published on: May 1, 2020

3.1K
Xenopus laevis as a Model to Identify Translation Impairment
10:24

Xenopus laevis as a Model to Identify Translation Impairment

Published on: September 27, 2015

10.7K

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Translation initiation is crucial for protein synthesis and is tightly regulated.
  • Dysregulation of translation initiation is implicated in various human diseases.
  • Eukaryotic initiation factors (eIFs), including eIF1 and eIF5, play key roles in start site selection.

Purpose of the Study:

  • To investigate the real-time function of eIF1 and eIF5 during human translation initiation.
  • To elucidate the roles of eIF1 and eIF5 in ensuring accurate start site selection.
  • To understand how eIF1 and eIF5 dynamics are modulated by RNA sequences and cellular levels.

Main Methods:

  • Single-molecule fluorescence analysis of in vitro reconstituted human translation initiation.
  • Real-time monitoring of eIF1 and eIF5 binding dynamics on messenger RNA.
  • In cellulo assays including knockdown and overexpression of eIF1 and eIF5.

Main Results:

  • eIF1 departure from the 43S initiation complex is rapid and start site-dependent, with delays caused by alternative sites or longer 5'UTRs.
  • eIF1 dynamically samples initiation complexes, with prolonged sampling at alternative start sites.
  • eIF5 binds transiently late in initiation, requiring a start site and inhibited by alternative sites.

Conclusions:

  • eIF1 and eIF5 exhibit opposing roles in translation initiation, controlling start site selection fidelity.
  • Multiple binding events of eIF1 and eIF5 precisely regulate start site accuracy.
  • The levels of eIF1 and eIF5 fine-tune translation initiation fidelity in response to cellular conditions.