Exam 1 is T 923 in class bring
• Exam #1 is T 9/23 in class (bring cheat sheet) Available M 9/22: 10 am-noon, 1: 30 -2: 30 pm, and after 3: 30 pm. T 9/23 after 10 am
How do cells express genes?
Tbl 12. 3
A processed m. RNA ready for translation 5’ untranslated region 3’ untranslated region
Sometimes RNA is the final product.
The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks Michael Kruhlak, Elizabeth E. Crouch, Marika Orlov, Carolina Montano, Stanislaw A. Gorski, Andre Nussenzweig, Tom Misteli, Robert D. Phair & Rafael Casellas Nature Vol 447 pg 730 -734 7 June 2007
How does DNA damage affect transcription? The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks Michael Kruhlak, Elizabeth E. Crouch, Marika Orlov, Carolina Montano, Stanislaw A. Gorski, Andre Nussenzweig, Tom Misteli, Robert D. Phair & Rafael Casellas Nature Vol 447 pg 730 -734 7 June 2007
r. RNA is transcribed by RNA polymerase I
comprised of r. RNA
r. DNA and transcription of r. RNA
r. DNA is arranged in repeated transcription units Fig 12. 16
Fig 12. 16 One transcript is then processed into the three major components of ribosomes
How can you measure transcription? Fig 1 a
DNA damage inhibits r. RNA transciption 0 Gy 10 Gy Fig 1 a
More irradiation leads to less transcription Fig 1 a
Transcription arrest is transitory Fig 1 b
DNA damage by laser. Only damaged nucleoli show decreased transcription. Fig 1 c
What cellular components are involved? Ku has been shown in vitro to inhibit RNA pol I after DNA damage. Atm kinase is part of signal transduction Fig following DNA breaks. 2 a
Atm must be phosphorylated to mediate the decrease in transcription Fig 2 b
Brca 1, H 2 ax, Ku 80, and 53 bp 1 are involved in DNA repair. Transcription arrest occurs, but resumption is delayed. Fig 2 c
DNA damage arrests r. RNA transcription via ATM
Combinations of 3 nucleotides code for each 1 amino acid in a protein. Fig 13. 2
Tbl 13. 2 The Genetic Code: 64 codons 20 amino acids 1 start codon 3 stop codons
Fig 12. 1 Translation involves different RNA’s Protein
• r. RNA folds up by intramolecular base pairing Fig 13. 16
• Ribosomes are made of both RNA and protein Fig 13. 15
• On the ribosome, the m. RNA, t. RNA’s, and growing polypeptide come together Fig 13. 16
• The structure of transfer RNA Fig 13. 12
Fig 13. 19 Translation initiation sequences along with the start codon signals the start of translation
• Translation initiation in eukaryotes Fig 13. 18
The poly-A tail and 5’ cap are involved in translation initiation
Tbl 13. 2 The Genetic Code: 64 codons 20 amino acids 1 start codon 3 stop codons
Redundancy in codons means that some t. RNAs bind to the codon via wobble Fig 13. 14
m. RNAs are usually translated by multiple ribosomes simultaneously
In bacteria, transcription and translation occur simultaneously Fig 13. 22
• Termination of translation by binding of release factor (a protein) to the stop codon Fig 13. 21
• All protein interactions in an organism (C. elegans) compose the interactome
RNA synthesis Protein post-translational modifications: activation, inactivation, destruction, and translocation
How do cells express genes?
• Exam #1 is T 9/23 in class (bring cheat sheet) Available M 9/22: 10 am-noon, 1: 30 -2: 30 pm, and after 3: 30 pm. T 9/23 after 10 am
- Slides: 41