Here is a brief description of the Regulatory features of 5’ nuclear mRNA.

1. Regulatory features of 5’
nuclear mRNA
Presented By:
Inchara R
9th Semester
Molecular Biology
22/01/2022
Guided By:
Cletus D’Souza
Emeritus Professor
Dept. of Biochemistry
University of Mysore
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2. CONTENTS
Introduction
Regulation of translation
• Ferritin Regulation
• Gcn4 Regulation
Conclusion
References
Acknowledgement
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3. INTRODUCTION
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4. INITITAION:
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FIG 01: Translation initiation in Eukaryotes

5. ELONGATION:
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FIG 02: Steps of translation elongation

6. TERMINATION:
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FIG 03: Eukaryotic translation termination and ribosome recycling

8. REGULATION OF TRANSLATION
• Stability and translation of mRNA can be regulated by 5’ and 3’ UTR
of mRNA.
Example is Ferritin Receptor mRNAs
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9. An Iron-Regulated, RNA-Binding Protein
Controls Translation of Ferritin
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FIG 04: Regulation of Ferritin translation by Iron

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FIG 05: Regulation of the expression of ferritin receptor

11. Translation of the Yeast Transcriptional
Activator Gcn4
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FIG 06: Gcn4 mRNA
• After translating uORF1, ribosomes can re-initiate at uORF2 (~50%)

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FIG 07: Translational control of Gcn4 in response to amino acid starvation
(a) When amino acids are abundant

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FIG 07: (b) under starvation conditions

14. Control of translation by eIF2 phosphorylation
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FIG 07: Reaction stimulated by Amino acid deprivation

15. CONCLUSION
SOME UNRESOLVED ISSUES
• A critical but poorly understood feature of GCN4 translational control
is the highly disparate capacities of uORF1 and uORF4 to permit
resumption of scanning following translation termination.
• It is also important to understand the molecular basis for activation of
Gcn2p by diverse starvation or stress conditions in amino acid-replete
cells.
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16. REFERENCES
• Mathews M.B., Sonenberg N., and Hershey J.W.B. 2007. Translational control in biology and
medicine. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 999pp.
• Robert F. Weaver. 2002. Molecular Biology, 5th Edition, the McGraw-Hill Companies, New York,
914pp.
• Watson, J. D., T. A. Baker, S. P. Bell, A. Gann, M. Levine, R. Losick. 2004. Molecular Biology of
the Gene. 5th Edition. Pearson Education Pte. Ltd., New Delhi, India, 911pp.
• Hinnebusch, A. G. (1997). Translational Regulation of YeastGCN4. Journal of Biological
Chemistry, 272(35), 21661–21664. https://doi.org/10.1074/jbc.272.35.21661
• Hinnebusch, A. G. (2005). Translational regulation of gcn4 and the general amino acid control of
yeast. Annual Review of Microbiology, 59(1), 407–450.
https://doi.org/10.1146/annurev.micro.59.031805.133833
• Gebauer, F., Hentze, M. (2004). Molecular mechanisms of translational control. Nat Rev Mol Cell
Biol 5, 827–835. https://doi.org/10.1038/nrm1488
• Janssen, B. D., & Hayes, C. S. (2012). The tmRNA ribosome-rescue system. Advances in protein
chemistry and structural biology, 86, 151–191.
https://doi.org/10.1016/B978-0-12-386497-0.00005-0
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17. • Balvay, L., Soto Rifo, R., Ricci, E. P., Decimo, D., & Ohlmann, T. (2009). Structural and functional
diversity of viral IRESes. Biochimica et biophysica acta, 1789(9-10), 542–557.
https://doi.org/10.1016/j.bbagrm.2009.07.005
• Dever, T. E., & Green, R. (2012). The elongation, termination, and recycling phases of translation in
eukaryotes. Cold Spring Harbor perspectives in biology, 4(7), a013706.
https://doi.org/10.1101/cshperspect.a013706
• Hernández G. (2008). Was the initiation of translation in early eukaryotes IRES-driven?. Trends in
biochemical sciences, 33(2), 58–64. https://doi.org/10.1016/j.tibs.2007.11.002
• Laursen, B. S., Sørensen, H. P., Mortensen, K. K., & Sperling-Petersen, H. U. (2005). Initiation of
protein synthesis in bacteria. Microbiology and molecular biology reviews : MMBR, 69(1), 101–123.
https://doi.org/10.1128/MMBR.69.1.101-123.2005
• Nilsson, J., & Nissen, P. (2005). Elongation factors on the ribosome. Current opinion in structural
biology, 15(3), 349–354. https://doi.org/10.1016/j.sbi.2005.05.004
• Nissen, P., Kjeldgaard, M., & Nyborg, J. (2000). Macromolecular mimicry. The EMBO
journal, 19(4), 489–495. https://doi.org/10.1093/emboj/19.4.489
• Sonenberg, N., & Hinnebusch, A. G. (2009). Regulation of translation initiation in eukaryotes:
mechanisms and biological targets. Cell, 136(4), 731–745. https://doi.org/10.1016/j.cell.2009.01.042
• Weinger, J. S., Parnell, K. M., Dorner, S., Green, R., & Strobel, S. A. (2004). Substrate-assisted
catalysis of peptide bond formation by the ribosome. Nature structural & molecular biology, 11(11),
1101–1106. https://doi.org/10.1038/nsmb841
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18. ACKNOWLEDGEMENT
I would like to thank the dept. of Molecular Biology for
providing this opportunity to present this seminar.
I would also like to thank my guide Prof. Cletus D’Souza
for his valuable guidance.
Thank you one and all.
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