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8/10/2019 Presentation Karch

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A p53 enhancer region regulates target genes throughchromatin conformations in cis and in trans.

Nichole Link, Paula Kurtz, Melissa ONeal,

Gianella Garcia-Hughes, and John M. Abrams

Presented by Aleksandra, Ambra, Lyudmil, Manuel.


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PLAN

1. INTRODUCTION2. RESULTS & METHODS3. CONCLUSIONS


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INTRODUCTION


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Figure 1 A (fragment) .Oncogene. 2007 Aug 9; 26(36):5184-93.

INTRODUCTION


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Figure 1 A (fragment) .Oncogene. 2007 Aug 9; 26(36):5184-93.

INTRODUCTION


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Fig 1 AGenes Dev. Nov 15, 2013; 27(22): 24332438.

RESULTS

Fig 1 A, B.Nature Protocols 6, 14121428 (2011)

FRT-mediated recombination

Deletions


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RESULTS

Fig 1 E, F.Genes Dev. Nov 15, 2013; 27(22): 24332438.

Acridine stains

p53-dependent stress-induced cell death


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RESULTS

Fig 1 B, C, D.Supplementary 1 A, B.Genes Dev. Nov 15, 2013; 27(22): 24332438.RIPD and control cDNAs

P53 is expressed inthe D2p53RE mutant


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Revisting 3C(Chromosome ConformationCapture)

Is this due to the formation of chromosome loops?


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Normalized to known interactions in bitorax complex


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No p53

Irradiation


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Is the p53RE present ectopically able to establish this contacts? Includeit in other chromosome(2)


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FISH experiment


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Fig.2

p53RE stablishes contact with its regulatory regions independently of:

Stress situation

Pressence of the p53 protein

Therefore, this contacts do not induct transcription by themselves.

This contacts can be rescued by ectopic presence of the p53RE.

p53RE is capable of stablishing contacts in trans, from farregions.


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RESULTS

Long distance control by the p53RE

xrp1 is nonresponsive in D2p53RE animals and D3control

stress-induced expression unchanged in D3control


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RESULTS

p53RE regulates xrp1

p53RE

xrp1

colocalizedsignal


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RESULTS

In vivo frequency of contact betweenp53 enhancer and xrp1

p53 enhancer makes physical contact to trans targets within only a subset ofcells at any given time


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RESULTS

p53RE can perform contacts with long-distance target sites from ectopic position intrans in a sequence-specific way.


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RESULTS

p53RE partially restores regulation from an ectopic position in trans


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Presence of contacts not sufficient for target


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p53RE can generate simultaneous contacts with multiple targets in a single cell

RESULTS

colocalization of al three loci within 23% of cells


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C O N C L U S I O N S

Single enhancer region regulation of multiple targets in cis and in trans

Transplanted to ectopic locationscontacts with target sites reestablished

regulation of some target genes was restored

p53regulatory

element

Stimulus dependentinduction of multiple genes

4 kb to 330 kb

xrp1a genetically unlinked target residing

across the centromere

long-range regulation by the p53RE involves chromosomal architectures that link thisenhancer to target genes regardless of whether they are in cis or in trans.


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