CSB349L15 - CSB349 Lecture 15 Regulation of the Message:...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
CSB349 Lecture 15 November 10 th Regulation of the Message: Cleavage and Polyadenylation Splicing controlled by protein interactions or by chromatin related proteins. .controlling alternative splicing. The form we are going to talk about is 3’ end processing. We already know about the 5’ cap. 3’ processing and splicing happen along the way that transcription is occurring. 3’ processing is coupled to termination of transcription.
Background image of page 1

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

View Full DocumentRight Arrow Icon
CSB349 Lecture 15 November 10 th There are differences b/w species for transcription termination. The current model has some of the cleavage and poly A factors are occurring at a time when transcription is going on but is just about to end. They may be involved in the process of termination. There are important signal sequences that are in the primary strand and when it’s created in the RNA, it will be recognized by a protein. CPSF binds to CTD end of RNA. The some how stops RNAPII from doing its job (not entirely known how).
Background image of page 2
CSB349 Lecture 15 November 10 th The polyA sequence is almost always AAUAAA. IT’s main role is to attract the complex of proteins that leads to cleavage and PolyA of the transcript. It’s located 10-15 nucleotides upstream. The polyA tail is not coded in DNA, only requires particular end sequence of transcript. The G/U rich regionand hexonucleotides help assemble the cleavage factors. CPSF and CstF, notice G/U and bind and the CFI and PAP help stabilize the structure. Virtually all RNAs are polyAed. . core histone genes (H3, H4, H2A, H1), are not polyadenylated. The histone genes are arrayed as tandem duplicates as clusters around the genome. There can be tens of hundreds of histone genes of the same type. So many of these need to be made, especially is DNA sequencing. Must be made fast. .so maybe why it’s not Polyadenylated.
Background image of page 3

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

View Full DocumentRight Arrow Icon
CSB349 Lecture 15 November 10 th Assembly of factors. CPSF binds AAUAAA and eventually a polyA binding proteins will bind. Even though primary transcript has been cleaved and the PAP is there, the polyA is a slow addition process (rate limiting step). Only goes fast when PABPII binds. ...once this is bound in the complex with PAP, it stimulates addition of A residues after 250 residues, then it stops. PABPII is what helps make faster and stop PAP from polyAing.
Background image of page 4
CSB349 Lecture 15
Background image of page 5

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

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/03/2010 for the course CSB CSB349 taught by Professor V.tropepe,a.moses during the Fall '10 term at University of Toronto- Toronto.

Page1 / 12

CSB349L15 - CSB349 Lecture 15 Regulation of the Message:...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online