CSB329H1 Lecture 7: Lecture 7 Part 2

40 views3 pages
Lecture 7(b): Embryonic Stem Cells
Leukemia Inhibitory Factor (LIF) Signaling:
Once LIF is added to the media, it will bind to a transmembrane
LIF receptor (LIFR) leading to the activation of Janus Kinase
(JAK)
o JAK will function to phosphorylate signal transducer
and activator of transcription (STAT)
§ STAT-P will translocate to the nucleus bind to
chromatin and activate gene transcription to
support self-renewal
Transcription Initiation:
Three transcription factors (OCT4, SOX2, NANOG) are known
as activators; function to bind to DNA and activate genes that
are critical regulators of cells state
o These transcription factors function in a large-complex
of transcription factors, known as an enhancesome
Enhancer site is a region on the DNA where an enhancer
(transcription factor) binds
o This DNA sequence will lead to the activate the transcription of a target gene in an
orientation-independent manner
§ Enhancers do not have to be in a specific orientation
§ Promotors activate transcription in an orientation dependent manner
DNA looping functions to bring the enhancer site physically close to the gene promotor
Enhancesome Model of Gene Regulation:
A full complex of transcription factors are required to activate gene transcription
o 1 TF, 2 TF, 3 TF are not sufficient; we require a full complex of
transcription factors
(i.e. just SOX2, is not sufficient, it requires the other partners to function)
Embryonic Stem Cell Enhancesome:
Enhancesome complex consists of:
o Phosphorylated STAT3
o OCT4, SOX2, NANOG
o KLF4
o Other factors (not yet known)
ð This complex functions to further recruit co-activators: mediator and chromatin
remodeling complexes
Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Lecture 7(b): embryonic stem cells: once lif is added to the media, it will bind to a transmembrane. Lif receptor (lifr) leading to the activation of janus kinase (jak: jak will function to phosphorylate signal transducer and activator of transcription (stat) Stat-p will translocate to the nucleus bind to chromatin and activate gene transcription to support self-renewal. Enhancers do not have to be in a specific orientation. Promotors activate transcription in an orientation dependent manner: dna looping functions to bring the enhancer site physically close to the gene promotor. Embryonic stem cell enhancesome: enhancesome complex consists of, phosphorylated stat3, oct4, sox2, nanog, klf4, other factors (not yet known) This complex functions to further recruit co-activators: mediator and chromatin remodeling complexes. Guest lecturer"s research trying to understand how es cell maintain their feature of pluripotency. Regulation of sox2 gene expression: sox2 gene; small intron-less gene.

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers

Related Documents

Related Questions