{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture 14 - Lecture 14 Regulation of Gene Expression in...

Info icon This preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 14 Regulation of Gene Expression in Eukaryotes
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
Overview of transcriptional regulation Eukaryotic DNA packaged into nucleosomes – regulatory proteins participate in exposing sequences for transcription
Image of page 2
Some differences in bacterial and eukaryotic transcriptional regulation bacteria eukaryotes All genes are transcribed by the same RNA polymerase Three RNA polymerases transcribe distinct subsets of genes Little or no processing of primary transcripts Extensive cotranscriptional processing; modification of 5’ and 3’ ends and intron splicing Relatively simple polymerase with a few associated factors RNA polymerase II is a large, complex collective – coordinates processing activities of associated proteins. Gene regulation in eukaryotes must: ensure that expression of most genes is off at any given time while specific subsets are activated generate the myriad patterns of gene expression that define cell types and developmental stages
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
Promoter proximal elements: complexity of eukaryotic promoters CAT box? Just kidding! Single base mutations in core promoter elements reduces transcription TATA box
Image of page 4
Promoter proximal elements are bound by GTFs…a second group of protein components consists of specific transcription factors that bind to cis -acting regulatory sequences in the DNA. These cis elements, which may be situated at a considerable distance(>50kb) from the promoter region (promoter-distal), are called enhancers or upstream activation sequences (UASs) Regulatory proteins must possess one or more of the following functional domains: 1.A domain that recognizes a DNA regulatory sequence (DNA binding site) 2.A domain that interacts with proteins of the transcriptional apparatus (polymerase or associated protein) 3.A domain that interacts with proteins bound to nearby regulatory sequences on DNA such that they can cooperatively regulate transcription 4.A domain that influences chromatin condensation either directly or indirectly 5.A domain that acts as a sensor of physiological conditions within the cell
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
The structure of chromatin Before any interaction can occur at promoter proximal or distal sites access must be facilitated via chromatin remodeling cells accomplish the specific exposure of regulatory elements and genes by changing the position of the nucleosome…
Image of page 6
Chromatin remodeling exposes regulatory sequences histone octamer regulatory element Changes in nucleosome density and position is an integral part of eukaryotic transcriptional control…
Image of page 7

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

View Full Document Right Arrow Icon
Histone tails protrude from the nucleosome…seven of eight histone monomers are shown, modifications are show on one tail, but all may be similarly modified.
Image of page 8
Image of page 9
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