*Coordination of PIC Assembly and Chromatin Remodeling During Differentiation-Induced Gene Activation*
http://www.umbc.edu/bioclass/biol414/readings/soutoglou.pdf

*A. Background Material*
 
Gene activity does not take place when DNA is being packaged into chromatin. It then makes sense that chromatin remodeling must take placein order for the preinitaiation complex to be formed.  This action is done by ATP complexes that alter the nucleosome and histone acetyltransferases that alter core histones. Sequential recruitment takes place that leads to the assembly of the final transcriptional initiation machinery.

*B. Materials and Methods*

-Alpha (1)-antitrypsin gene was used to study chromatin reconfiguration and preinitiation complex formation. 
-CaCo-2 cells were used to express marker genes such as alpha(1)-antitrypsin.
-RT-PCR and S1 nuclease protection assay was used to detect mRNA 
-Low-resolution nucleosome mapping by indirect end-labelling of MNase was used to visualize nucleosomes.
-Ligation-mediated PCR was used to determine nucleosome borders.
-Restriction enzyme hypersensitivity assays were used to find any conformational changes
-ChIP and re-ChIP assays were performed

*C. Research Results*

-No 5'-truncated transcripts accumulated.
-Several nucleosomes were present.
-The positions of NUC1, NUC2, HNF-1,HNF-4 were determined.
-NUC2 had a conformational change.
-alpha(1)-antitrypsin is constitutively associated with the promoter.
-TBP and TFIIB are found on the promoter throughout differentiation.
-TAFII-250 and TAFII-30 are not found on the promoter in pre-differentiated cells.
-NUC1 and NUC2 do not undergo repositioning upon differentiation.

*D. Interpretation and Future Prospects*

-Nucleosome acetylation plays a role in transcription initiation.
-ASsembly takes place before chromatin remodelling.

 
*E. Questions*

Where do CaCo-2 cells come from?

*Author* :A.D.Howard



*Author* :A.D. Howard