title: Discovering high mobility group A molecular partners in tumour cells.
abstract: DNA-based activities rely on an extremely coordinated sequence of events performed by several chromatin-associated proteins which act in concert. High Mobility Group A (HMGA) proteins are non-histone architectural nuclear factors that participate in the regulation of specific genes but they are also believed to have a more general role in chromatin dynamics. The peculiarity of these proteins is their flexibility, both in terms of DNA-binding and in protein-protein interactions. Since these proteins act as core elements in the assembly of multiprotein complexes called enhanceosomes, and have already displayed the ability to interact with several different proteins, we started a proteomic approach for the systematic identification of their molecular partners. By a combination of affinity chromatography, two-dimensional gel electrophoresis and mass spectrometry we have identified about twenty putative HMGA interactors which could be roughly assigned to three different classes: mRNA processing proteins, chromatin remodelling related factors and structural proteins. Direct HMGA interaction with some of these proteins was confirmed by glutathione-S-transferase pull-down assays and the HMGA domain involved was mapped. Blot-overlay experiments reveal that members of the HMGA family share most of their molecular partners but, interestingly, it seems that there are some cell-type specific partners. Taken together, these experimental data indicate that HMGA proteins are highly connected nodes in the chromatin protein network. Since these proteins are strongly implicated with cancer development, the identification of molecules able to perturb the HMGA molecular network could be a possible tool to interfere with their oncogenic activity.
authors.affiliation: Dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole, Università di Trieste, Trieste, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Sgarra
authors.forename: Michela A
authors.initials: MA
authors.lastname: Tessari
authors.forename: Julie
authors.initials: J
authors.lastname: Di Bernardo
authors.forename: Alessandra
authors.initials: A
authors.lastname: Rustighi
authors.forename: Paola
authors.initials: P
authors.lastname: Zago
authors.forename: Sabrina
authors.initials: S
authors.lastname: Liberatori
authors.forename: Alessandro
authors.initials: A
authors.lastname: Armini
authors.forename: Luca
authors.initials: L
authors.lastname: Bini
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Giancotti
authors.forename: Guidalberto
authors.initials: G
authors.lastname: Manfioletti
mesh_terms: D045744:Cell Line, Tumor; D002843:Chromatin / Q000378:metabolism*; D002846:Chromatography, Affinity; D015180:Electrophoresis, Gel, Two-Dimensional; D005982:Glutathione Transferase / Q000378:metabolism; D024003:HMGA Proteins / Q000378:metabolism*; D006801:Humans; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020543:Proteome / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002843:Chromatin; D024003:HMGA Proteins; D020543:Proteome; D012333:RNA, Messenger; D011994:Recombinant Proteins; D005982:Glutathione Transferase