1 / 17

Messenger RNA Nomenclature and Visualization in Protein Synthesis

Learn about messenger RNA (mRNA) nomenclature, pre-mRNA processing, spliced mRNAs, RNA polymerase, transcription factors, and mRNA secondary structure in protein synthesis. Discover the history and techniques of visualizing mRNA in the synthesis pathway.

benjaminpittman
Download Presentation

Messenger RNA Nomenclature and Visualization in Protein Synthesis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Messenger RNA Todd Metzger BMS 265 May 8, 2009

  2. Nomenclature • Messenger RNAs (mRNA) describes cytoplasmic product • Pre-mRNA (part of hnRNA) in nucleus is processed and exported • Describe by gene/protein, including isoform • or NCBI sequence (NM, natural; XM, in silico) • New methods for describing spliced mRNAs (Sammeth 2008)

  3. 1955 - Goldstein and Plaut 6 min 62 hr

  4. Discovery • Volkin and Astrachan discovered a new type of RNA synthesized following infection of bacteria by T2 Bacteriophage (Volkin 1956) • Newly synthesized RNA mirrored composition of T2 DNA • Brenner, Jacob, and Meselson found that only RNA, and not ribosomes, were newly synthesized following infection (1961) • The term messenger RNA was coined

  5. Translation Leads to Linear Protein Synthesis • Dintzis 1961 • Reticulocytes analyzed • Make ~90% hemoglobin • Radiolabeled amino acids incorporated to C-terminus only

  6. 1970 - Messenger RNA VisualizedMiller et al

  7. Biogenesis • Enzymatic Reaction by RNA Polymerase • RNA Pol II in eukaryotes • Involves Initiation Factors (TFIIB,D,E,F,H) and Mediator Complex • Core RNA polymerase II is 12 subunits, 500 kDA, highly conserved • 10 subunit catalytic core Woychik 2002, Sims III 2004

  8. Yeast RNA pol II Catalytic core Positively charged cleft Active site occurs between the wall and clamp (shown closed - elongation)

  9. Transcription • Template DNA, 5 GTFs, and RNA pol II associated to form pre-initiation complex • TFIID contains the TATA-box binding protein (TBP) • TFIIE and -H melt DNA • CTD phosphorylation is required for dissociation of initiation factors and entrance to the elongation phase • TFIIS allows stalled transcription to continue • Reverse procession followed by cleaved of RNA

  10. TFIIS

  11. Mediator • Connects transcription factors to basal machinery Casamassimi 2007

  12. mRNA Secondary Structure • Many mRNAs can code for the same protein • Made program to scramble codons while preserving base content • Looked at 50 bp structures Katz 2003

  13. mRNA Secondary Structure - No significant differences for human sequences

  14. mRNA Vaccinations - Direct Hess et al 2006

  15. mRNA Vaccinations - Indirect Hess et al 2006

More Related