Posters
« Back
A proteomic analysis of p27<sup>kip1</sup>-binding proteins reveals a putative role in transcription regulation through RNA polymerase II interaction
EP22973
Poster Title: A proteomic analysis of p27kip1-binding proteins reveals a putative role in transcription regulation through RNA polymerase II interaction
Submitted on 11 May 2015
Author(s): Juan Triviño Paredes1, Atilla Biçer1, Arnauld Besson2, Edurne Gallastegui1, Josep Maria Estanyol3, Maria Jesus Pujol1 and Oriol Bachs1
Affiliations: 1.-Department of Cell Biology, Immunology and Neurosciences, University of Barcelona-IDIBAPS, Barcelona, Spain 2.-INSERM UMR1037-Cancer Research Center of Tolouse, Universite de Tolouse, CNRS ERL5294 Tolouse, France 3.-Proteomic Unit, Centres Científics I Tecnologics, University of Barcelona, Barcelona, Spain
This poster was presented at 13th World Congress of the Human Proteome Organization
Poster Views: 2,246
View poster »


Poster Information
Abstract: Introduction and objectives: The protein p27(kip1) is a member of the Cip-Kip family of cyclin-dependent kinase (CDK) inhibitors. In addition to this role, p27 also behaves as a transcriptional regulator. It directly interacts with the p130/E2F4 subunit of the DREAM transcriptional repressor complex through its carboxyl moiety. To further identify new mechanism of transcriptional regulation mediated by p27 we aimed to identify nuclear proteins that associates with its carboxyl terminal domain.

Methods: Affinity chromatography columns of p27 peptide (including a.a. 161-198) bound to sepharose-beads was used to purify p27-binding proteins (p27-BPs). These proteins were subsequently identified by mass spectrometry (MS).

Results and Discussion: MS analysis of the purified p27-BPs revealed that 8 subunits of RNA polymerase II (RNA pol II) associate with p27.
The interaction of p27 with RNA pol II was validated by immunoprecipitation (IP) analysis using anti-p27 antibodies.
A subsequent Proto-Array analysis identified the RNA pol II-K subunit as the direct target of p27. This direct interaction was validated by affinity chromatography using purified proteins.
Finally, by Chromatin-IP (ChIP) we could establish a correlation between the loading of RNA pol II on the promoters of specific target genes and the presence of p27 on these promoters.
Conclusions: The protein p27Kip1 might regulate transcription by loading RNA polymerase II on the promoters of specific target genes.
Summary: A proteomic analysis of p27kip1-binding proteins reveals a putative role in transcription regulation through RNA polymerase II interactionReferences: 1.-Pippa, R., Espinosa, L., Gundem, G., Garcia-Escudero, R., Dominguez, A., Orlando, S., Gallastegui, E., Saiz, C., Besson, A., Pujol, M.J., Lopez-Bigas,
N., Paramio, J.M., Bigas, A. & Bachs, O. 2012, "p27Kip1 represses transcription by direct interaction with p130/E2F4 at the promoters of target genes",
Oncogene, vol. 31, no. 38, pp. 4207-4220.

2. Souza-Rodrígues E, Estanyol JM, Friedrich-Heineken E, Olmedo E, Vera J, Canela N, Brun S, Agell N, Hübscher U, Bachs O, Jaumot M. Proteomic
analysis of p16ink4a-binding proteins. Proteomics. 2007 Nov;7(22):4102-11
Report abuse »
Questions
Ask the author a question about this poster.
Ask a Question »

Creative Commons