Research Groups

Molecular Pathology

Research Interests and Description

Research Interests

Molecular mechanisms of pre-mRNA processing. RNA-protein interactions. Defective RNA processing and neurodegeneration. Genetic disease caused by defective splicing.

Description of Research

The objectives of the Group are to investigate aberrant pre-mRNA processing defects that lead to disease in humans with special emphasis placed upon developing novel therapeutic approaches. In addition, recent developments have brought us to study the involvement of RNA binding proteins in neurodegeneration. With regards to pre-mRNA splicing defects, in the past our Group has focused on a variety of genes that include CFTR, NF-1, and ATM. Presently, we are investigating a series of mutually exclusion splicing events in two mammalian sodium channel alfa subunit genes, SCN8A and SCN9A. Mutations in the SCN9A gene have been associated with various pain-related syndromes. In genes with pairs of mutually exclusive exons, only one of the exons in the pair is included in the mature mRNA, whereas the other is excluded. These genes are currently investigated with the aim of obtaining additional information with regards to the cis- and trans-acting factors that regulate this type of unconventional splicing mechanism. Particular emphasis will then be placed upon the potential correction of aberrant splicing events that concern these genes using the numerous methodologies that have been developed just for this purpose in recent years. This will hopefully pave the way for a clinical evaluation of the most successful effectors in a human setting.
In parallel with these studies, we have continued our study of the molecular mechanisms that control (and are controlled by) the TDP-43 protein. Our laboratory initially identified this protein in 2001 as a splicing regulator of CFTR exon 9 splicing. In 2006, TDP-43 was found as the major protein component of the intracellular inclusions occurring in the neuronal tissues of patients affected by a series of neurodegenerative diseases which include Amyotrophic Lateral Sclerosis and Fronto-temporal dementia. In the patient’s affected neurons, TDP-43 is abnormally mislocalized in the cytoplasm, ubiquitinated, hyperphosphorylated and cleaved to generate C-terminal fragments. Presently one of the most likely hypotheses is that such mislocalization may play a pivotal role in neurodegeneration through the loss of proper TDP-43 function(s) in the nucleus (“loss-of-function” effects). Therefore, many of our recent analyses have been aimed at better characterizing the basic molecular properties of TDP-43. In turn, this will allow us to better understand which functions/pathways are most likely to be affected in the disease state. Our work on this protein has contributed to explain several molecular aspects of this protein: its nucleo-cytoplasmic shuttling properties, further insight into its pre-mRNA splicing properties and its potential involvement in microRNA regulation. Most recently, using stable cell lines that can inducibly express mutants of this protein, we have observed that TDP-43 can regulate its own pre-mRNA levels by binding to specific regions in its 3'UTR sequence using a negative feedback loop mechanism. These findings have demonstrated for the first time that cellular TDP-43 levels are under tight control and it is likely that disease-associated TDP-43 aggregates disrupt TDP-43 self-regulation, thus contributing to pathogenesis.

Recent Publications

Budini, E., Buratti, E. 2011. TDP-43 autoregulation: implications for disease. J. Mol. Neurosci. (in press)

Ayala, Y.M., De Conti, L., Vázquez, S.E.A., Dhir, A., Romano, M., D’Ambrogio, A., Tollervey, J., Ule, J., Baralle, M.,Buratti, E., Baralle, F.E. 2011. TDP-43 regulates its mRNA levels through a negative feedback loop. EMBO J. 30, 277-288 PubMed link

Zago, P., Buratti, E., Stuani, C., Baralle, F.E. 2011. Evolutionary connections between coding and splicing regulatory regions in the fibronectin EDA exon. J. Mol. Biol. 411, 1-15 PubMed link

Buratti, E., De Conti, L., Stuani, C., Romano, M., Baralle, M., Baralle, F.E. 2010. Nuclear factor TDP-43 can affect selected microRNA levels. FEBS J. 277, 2268-2281 PubMed link

Dhir, A., Buratti, E., van Santen, M.A., Lührmann, R., Baralle, F.E. 2010. The intronic splicing code: multiple factors involved in ATM pseudoexon definition. EMBO J. 29, 749-760 PubMed link

Haque, A., Buratti, E., Baralle F.E. 2010. Functional properties and evolutionary splicing constraints on a Composite Exonic Regulatory Element of Splicing (CERES) in CFTR exon 12. Nucleic Acids Res. 38, 647-659 PubMed link