lec 14-15 - Key concepts Each stage of translation requires...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Key concepts Each stage of translation requires specific proteins called initiation factors , elongation factors , and release factors . Initiation involves recruitment of the initiator tRNA to the small ribosomal subunit, recruitment of the mRNA, recognition of the start codon, and recruitment of the large ribosomal subunit. Recruitment of the mRNA usually involves an interaction of an initiation factor (eIF4E) with the 5’ cap structure of mRNA. Cap-independent translation can also occur.
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Key concepts Elongation proceeds through a repetitive 4-step cycle: binding of incoming aminoacyl-tRNA to the A site, conformation shift of ribosome accompanied by release of previously used tRNA from the E site, transfer of the growing peptide chain to the incoming amino acid, and translocation of the ribosome to the next codon. Termination factors (release factors) recognize stop codons and cleave the polypeptide from tRNA. Efficiency of protein synthesis is increased by simultaneous translation of a single mRNA by multiple ribosomes (polyribosomes, or polysomes). Re-initiation of protein synthesis is promoted by an interaction between eIF4G and PABP, which brings the 3’ and 5’ ends of the mRNA close together (circularizing the mRNA).
Image of page 2
Post-Transcriptional Gene Silencing
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
RNA interference First discovered as an artificially-induced experimental phenomenon Injection of antisense RNA targeted against a specific mRNA into a cell or embryo represses translation of the target mRNA.
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern