DNA Breaks


Vasco Barreto

Principal Investigator



Campus Sant'Ana
Pólo de Investigação, NMS, UNL
Rua Câmara Pestana, nº 6
1150-082 Lisboa, Portugal

Phone: (+351) 214 464 551
Fax: (+351) 218 851 920
E-mail: vasco.barreto(at)nms.unl.pt

Main Interests:

We explore the two hallmarks of the immunoglobulin (Ig) genes, allelic exclusion and somatic DNA editing, as stepping stones to gain genetic and quantitative insights into related and broader fields, namely the epigenetics of mono-allelic expression and the interplay between the B-cell DNA editing enzymes and DNA repair. We maintain a long-term interest in V(D)J recombination, somatic hypermutation and class-switch recombination, and we approach these phenomena from both evolutionary and mechanistic angles, relying mostly on molecular and cellular biology.


  • Ramiro, A. and Barreto, VM (2015) Activation-induced cytidine deaminase and active cytidine demethylation. Trends in Biochemical Sciences 40(3):172-81. DOI: 10.1016/j.tibs.2015.01.006
  • Pereira CF, Freitas R., Lopes T., Gardner R., Marta F., Vieira P., Barreto VM (2014) Independent recruitment of Igh alleles in V(D)J recombination. Nature Communications 5: 5623 DOI:10.1038/ncomms6623
  • Caratão N, Cortesão CS, Reis PH, Freitas RF, Jacob CM, Pastorino AC, Carneiro-Sampaio M, Barreto VM (2013) A novel activation-induced cytidine deaminase (AID) mutation in Brazilian patients with hyper-IgM type 2 syndrome. Clin Immunol. 148(2):279-286. DOI: 10.1016/j.clim.2013.05.017
  • Trancoso I, Bonnet M, Gardner R, Carneiro J, Barreto VM, Demengeot J, Sarmento LM. (2013) A Novel Quantitative Fluorescent Reporter Assay for RAG Targets and RAG Activity. Front Immunol.16;4:110. DOI: 10.3389/fimmu.2013.00110
  • Cortesao C S, Freitas RF, Barreto VM. (2013) Activation-Induced Cytidine Deaminase Does Not Impact on Murine Meiotic Recombination G3 (Bethesda, Md.) 3:645-655 DOI: 10.1534/g3.113.005553
  • Pavri R, Gazumyan A, Jankovic M, Di Virgilio M, Klein I, Ansarah-Sobrinho C, Resch W, Yamane A, Reina San-Martin B, Barreto VM, Nieland TJ, Root DE, Casellas R, Nussenzweig MC. (2010) Activation-induced cytidine deaminase targets DNA at sites of RNA polymerase II stalling by interaction with Spt5. Cell 143(1):122-33 DOI: 10.1016/j.cell.2010.09.017
  • Barreto VM, Pan-Hammarstrom Q, Zhao Y, Hammarstrom L, Misulovin Z, Nussenzweig (2005) AID from bony fish catalyzes class switch recombination. Journal of Experimental Medicine 202(6):733-8 DOI: 10.1084/jem.20051378
  • McBride KM, Barreto V, Ramiro AR, Stavropoulos P, Nussenzweig MC. (2004). Somatic Hypermutation Is Limited by CRM1-dependent Nuclear Export of Activation- induced Deaminase. Journal of Experimental Medicine 199(9):1235-44 DOI: 10.1084/jem.20040373
  • Yannoutsos N, Barreto V, Misulovin Z, Gazumyan A, Yu W., Rajewsky , Peixoto BR, Eisenreich T., and Nussenzeig, M.C. (2004) A cis element in the recombinase activating gene locus regulates gene expression by counteracting a distant silencer. Nature Immunology 5(4):443-50 DOI: 10.1038/ni1053
  • Barreto V, Reina-San-Martin B, Ramiro AR, McBride KM, and Nussenzweig MC (2003). C-terminal deletion of AID uncouples class switch recombination from somatic hypermutation and gene conversion. Molecular Cell 12, 501-508.


Team photos