Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2010 Jul 9;285(28):21197-201.
doi: 10.1074/jbc.R110.111476. Epub 2010 May 5.

Eukaryotic protein synthesis: still a mystery

William C Merrick  1
Affiliations

Eukaryotic protein synthesis: still a mystery

William C Merrick. J Biol Chem. .
No abstract available

PubMed Disclaimer

Figures

FIGURE 1.
FIGURE 1.
The eukaryotic 80 S initiation pathway. A general scheme for the initiation steps in eukaryotic translation (m7G cap-dependent) is depicted. Elements that are uncertain are discussed in the text. This figure is adapted from Fig. 8 in Ref. .
FIGURE 2.
FIGURE 2.
The process of reinitiation as seen in a model of the GCN4 mRNA. A ribosome is depicted having just completed the translation of the first small open reading frame (ORF1). At termination, the 60 S subunit is released, as are most, but not all, of the 40 S subunits. 40 S subunits that remain bound to the mRNA have a probability of acquiring a new ternary complex (3°) that is greatest under conditions of optimal protein synthesis (High 3°) but not under conditions of reduced protein synthesis (Low 3°). The probability of acquiring this second ternary complex is plotted below the schematic of the GCN4 mRNA. Initiation at ORF2 leads to termination and complete release of all subunits. Acquisition of a ternary complex 3′ of the AUG in ORF2 leads to the synthesis of GCN4 protein.
FIGURE 3.
FIGURE 3.
Alternate pathways for initiation complex formation that are more competitive for limiting amounts of the ternary complex (eIF2·GTP·met-tRNAi). A shows the “normal, m7G cap-dependent” pathway for initiation where ternary complex binding precedes binding of the mRNA. B shows the possibility of the mRNA binding to the 40 S subunit prior to the binding of the ternary complex. C shows the possibility of an MFC preferentially sequestering both the mRNA and the ternary complex prior to both binding to the 40 S subunit. Options in either B or C would make translation of IRES-containing mRNAs less sensitive to the global reduction of ternary complexes.
See this image and copyright information in PMC

References

    1. Kozak M. (1980) Cell 19, 79–90 - PubMed
    1. Parkin N. T., Cohen E. A., Darveau A., Rosen C., Haseltine W., Sonenberg N. (1988) EMBO J. 7, 2831–2837 - PMC - PubMed
    1. Kozak M. (1986) Cell 44, 283–292 - PubMed
    1. Svitkin Y. V., Pause A., Haghighat A., Pyronnet S., Witherell G., Belsham G. J., Sonenberg N. (2001) RNA 7, 382–394 - PMC - PubMed
    1. Godefroy-Colburn T., Thach R. E. (1981) J. Biol. Chem. 256, 11762–11773 - PubMed

MeSH terms