Lasa, M. (Marta)
- Publications
- item.page.relationships.isContributorAdvisorOfPublication
- item.page.relationships.isContributorOfPublication
3 results
Search Results
Now showing 1 - 3 of 3
- Characterization of the human Nalpha-terminal acetyltransferase B enzymatic complex(BioMed Central, 2009) Ametzazurra, A. (Amagoia); Larrea, E. (Esther); Aldabe, R. (Rafael); Lasa, M. (Marta); Prieto, J. (Jesús); Gazquez, C. (Cristina)BACKGROUND: Human Nalpha-acetyltransferase complex B (hNatB) is integrated by hNaa20p (hNAT5/hNAT3) and hNaa25p (hMDM20) proteins. Previous data have shown that this enzymatic complex is implicated in cell cycle progression and carcinogenesis. In yeast this enzyme acetylates peptides composed by methionine and aspartic acid or glutamic acid in their first two positions respectively and it has been shown the same specificity in human cells. METHODS: We have silenced hNAA20 expression in hepatic cell lines using recombinant adenoviruses that express specific siRNAs against this gene and analyzed cell cycle progression and apoptosis induction after this treatment. Immunopurified hNatB enzymatic complexes from human cell lines were used for analyzing hNatB in vitro enzymatic activity using as substrate peptides predicted to be acetylated by NatB. RESULTS: hNAA20 silencing in hepatic cell lines reduces cell proliferation in a p53 dependent and independent manner. At the same time this treatment sensitizes the cells to a proapototic stimulus. We have observed that the hNatB complex isolated from human cell lines can acetylate in vitro peptides that present an aspartic or glutamic acid in their second position as has been described in yeast. CONCLUSION: hNatB enzymatic complex is implicated in cell cycle progression but it exerts its effects through different mechanisms depending on the cellular characteristics. This is achievable because it can acetylate a great number of peptides composed by an aspartic or glutamic acid at their second residue and therefore it can regulate the activity of a great number of proteins.
- Flow cytometry for fast screening and automated risk assessment in systemic light-chain amyloidosis(Nature, 2019) González, M.E. (María Esther); Cedena, M.T. (María Teresa); Verde, J. (Javier); Pérez, J.J. (José J.); Martínez-López, J. (Joaquín); Krsnik, I. (Isabel); Gironella, M. (Mercedes); Orfao, A. (Alberto); Vidriales, M.B. (María Belén); Ocio, E.M. (Enrique M.); Mateos, M.V. (María Victoria); Arriba, F. (Felipe) de; Puerta, J.E. (José Enrique) de la; Puig, N. (Noemí); Labrador, J. (Jorge); Burgos, L. (Leire); Lasa, M. (Marta); Palomera, L. (Luis); Lahuerta, J.J. (Juan José); Pérez-Montaña, A. (Albert); Gómez-Toboso, D. (Dolores); Paiva, B. (Bruno); Lecumberri, R. (Ramón); Oriol, A. (Albert); Rubia, J. (Javier) de la; Prosper-Cardoso, F. (Felipe); Casanova, M. (María); Lecrevisse, Q. (Quentin); Merino, J. (Juana); San-Miguel, J.F. (Jesús F.); Moreno, C. (Cristina); Cabañas, V. (Valentín); García-de-Coca, A. (Alfonso)Early diagnosis and risk stratification are key to improve outcomes in light-chain (AL) amyloidosis. Here we used multidimensional-flow-cytometry (MFC) to characterize bone marrow (BM) plasma cells (PCs) from a series of 166 patients including newly-diagnosed AL amyloidosis (N = 94), MGUS (N = 20) and multiple myeloma (MM, N = 52) vs. healthy adults (N = 30). MFC detected clonality in virtually all AL amyloidosis (99%) patients. Furthermore, we developed an automated risk-stratification system based on BMPCs features, with independent prognostic impact on progression-free and overall survival of AL amyloidosis patients (hazard ratio: ≥ 2.9;P ≤ .03). Simultaneous assessment of the clonal PCs immunophenotypic protein expression profile and the BM cellular composition, mapped AL amyloidosis in the crossroad between MGUS and MM; however, lack of homogenously-positive CD56 expression, reduction of B-cell precursors and a predominantly-clonal PC compartment in the absence of an MM-like tumor PC expansion, emerged as hallmarks of AL amyloidosis (ROC-AUC = 0.74;P < .001), and might potentially be used as biomarkers for the identification of MGUS and MM patients, who are candidates for monitoring pre-symptomatic organ damage related to AL amyloidosis. Altogether, this study addressed the need for consensus on how to use flow cytometry in AL amyloidosis, and proposes a standardized MFC-based automated risk classification ready for implementation in clinical practice.
- N-terminal acetylation mutants affect alpha-synuclein stability, protein levels and neuronal toxicity(Elsevier, 2020) Aldabe, R. (Rafael); Fernandez-Irigoyen, J. (Joaquín); Aragón, T. (Tomás); Lasa, M. (Marta); Íñigo-Marco, I. (Ignacio); Bugallo, R. (Ricardo); Arrasate, M. (Montserrat); Larrea, L. (Laura); Carte, B. (Beatriz); Santamaria, E. (Enrique); Vinueza-Gavilanes, R. (Rodrigo)Alpha-synuclein (aSyn) protein levels are sufficient to drive Parkinson's disease (PD) and other synucleinopathies. Despite the biomedical/therapeutic potential of aSyn protein regulation, little is known about mechanisms that limit/control aSyn levels. Here, we investigate the role of a post-translational modification, Nterminal acetylation, in aSyn neurotoxicity. N-terminal acetylation occurs in all aSyn molecules and has been proposed to determine its lipid binding and aggregation capacities; however, its effect in aSyn stability/neurotoxicity has not been evaluated. We generated N-terminal mutants that alter or block physiological aSyn Nterminal acetylation in wild-type or pathological mutant E46K aSyn versions and confirmed N-terminal acetylation status by mass spectrometry. By optical pulse-labeling in living primary neurons we documented a reduced half-life and accumulation of aSyn N-terminal mutants. To analyze the effect of N-terminal acetylation mutants in neuronal toxicity we took advantage of a neuronal model where aSyn toxicity was scored by longitudinal survival analysis. Salient features of aSyn neurotoxicity were previously investigated with this approach. aSyn-dependent neuronal death was recapitulated either by higher aSyn protein levels in the case of WT aSyn, or by the combined effect of protein levels and enhanced neurotoxicity conveyed by the E46K mutation. aSyn Nterminal mutations decreased E46K aSyn-dependent neuronal death both by reducing protein levels and, importantly, by reducing the intrinsic E46K aSyn toxicity, being the D2P mutant the least toxic. Together, our results illustrate that the N-terminus determines, most likely through its acetylation, aSyn protein levels and toxicity, identifying this modification as a potential therapeutic target.