Genetics and Molecular Physiology

Pablo Wappner - Fundación Instituto Leloir

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Research in the lab - General Directions

Under oxygen deprivation (hypoxia), animal cells modify their gene expression pattern to re-establish energetic balance and homeostasis. This adaptive response is mediated mainly by the Hypoxia-Inducible Factor (HIF), a heterodimeric transcription factor of the bHLH-PAS family. We combine genetic experiments in vivo in Drosophila with assays in cell culture, to define mechanisms that mediate developmental and molecular adaptations to hypoxia.

1. Screen for new HIF regulators

We have conducted a genome-wide RNAi screen in Drosophila cells and identified new regulators of the hypoxic response (Dekanty et al. 2010). We are currently working on the definition of the mechanisms of action of these newly-identified hypoxia regulators, which include transcriptional and translational regulators, chromatin modifiers and miRNAs

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2. Adaptation to hypoxia and activation of autophagy

We have identified a plasma membrane immunophilin, which we have named “Zonda”, that participates of the regulation of the response to hypoxia. In addition to its role as a HIF regulator, Zonda plays a major role at early steps of the process of autophagy. We are currently characterizing in detail the molecular function of Zonda in autophagy, as well as the connection between hypoxic responses and activation of the autophagy cascade.

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3. miRNAs involved in HIF regulation

Argonaute1 (Ago1), and other components of miRNA machinery, have emerged from the genome wide screen as elements critically required for HIF-dependent responses to hypoxia (Dekanty et al. 2010). More recently, we identified miR-190 and other specific miRNAs  that contribute to HIF-dependent responses (De Lella Ezcurra et al. 2016), and are now trying to define their molecular targets and mechanisms by which they enhance the response to hypoxia.

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4. HIF translational regulation

While searching for miRNA binding sites at the 3’UTRs of messenger RNAs of HIF subunits, we identified consensus sequences for the RNA translational repressor Musashi. We demonstrated that Musashi controls HIF translation (Bertolin et al. 2016) and are currently characterizing physiological functions of the Musashi-HIF axis in development and cell differentiation.

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Markolovic S, Zhuang Q, Wilkins SE, Eaton CD, Abboud MI, Katz MJ, McNeil HE, Leśniak RK, Hall C, Struwe WB, Konietzny R, Davis S, Yang M, Ge W, Benesch JLP, Kessler BM, Ratcliffe PJ, Cockman ME, Fischer R, Wappner P, Chowdhury R, Coleman ML, Schofield CJ. The Jumonji-C oxygenase JMJD7 catalyzes (3S)-lysyl hydroxylation of TRAFAC GTPases. Nat Chem Biol. 2018 Jul;14(7):688-695 PubMed

Gándara L, Wappner, P. Metabo-Devo: A metabolic perspective of development. Mech Dev. 2018 Feb 21. pii: S0925-4773(18)30001-7. Review PubMed 

Melani, M., Valko, A., Romero, N.M., Aguilera, M.O., Acevedo, J.M., Bhujabal, Z., Perez-Perri, J., de la Riva-Carrasco, R.V., Katz, M.J., Sorianello, E., D'Alessio, C., Juhász, G., Johansen, T., Colombo, M.I., Wappner, P. Zonda is a novel early component of the autophagy pathway in DrosophilaMol Biol Cell. 2017 Sep 13. doi: 10.1091/mbc.E16-11-0767. [Epub ahead of print] PubMed

Perez-Perri, J.I., Dengler, V.L., Audetat, A.K., Pandey, A., Bonner, E.A., Urh, M., Mendez, J., Daniels, D.L., Wappner, P., Galbraith, M.D., Espinosa, J.M. The TIP60 complex is a conserved coactivator of HIF1A. Cell Reports. 2016 Jun 28;16(1):37-47. PubMed

De Lella Ezcurra, A.L., Bertolin, A.P., Kim, K., Katz, M.J., Gándara, L., Misra, T., Luschnig, S., Perrimon, N., Melani, M., Wappner, P. miR-190 Enhances HIF-Dependent Responses to Hypoxia in Drosophila by Inhibiting the Prolyl-4-hydroxylase Fatiga. PLoS Genet. 2016 May 25;12(5):e1006073. PubMed

Bertolin, A.P., Katz, M.J., Yano, M., Pozzi, B., Acevedo, J.M., Blanco-Obregón, D., Gándara, L., Sorianello, E., Kanda, H., Okano, H., Srebrow, A., Wappner, P. Musashi mediates translational repression of the Drosophila hypoxia inducible factor. Nucleic Acids Res. 2016 May 3 PubMed

Katz, M.J., Gandara, L., De Lella Ezcurra, A.L., Wappner, P. Hydroxylation and translational adaptation to stress: some answers lie beyond the STOP codon. Cell Mol Life Sci. 2016 Feb 13. Review PubMed

Simpson, P.D., Eipper, B.A., Katz, M.J., Gandara, L., Wappner, P., Fischer, R., Hodson, E.J., Ratcliffe, P.J., Masson, N. Striking Oxygen Sensitivity of the Peptidylglycine α-Amidating Monooxygenase (PAM) in Neuroendocrine Cells. J Biol Chem. 2015 Oct 9;290(41):24891-901. PubMed

Katz, M.J., Acevedo, J.M., Wappner, P. Growing with the wind. Ribosomal protein hydroxylation and cell growth. Fly (Austin). 2014;8(3):153-6. Review PubMed

Singleton, R.S., Liu-Yi, P., Formenti, F., Ge, W., Sekirnik, R., Fischer, R., Adam, J., Pollard, P.J., Wolf, A., Thalhammer, A., Loenarz, C., Flashman, E., Yamamoto, A., Coleman, M.L., Kessler, B.M., Wappner, P., Schofield, C.J., Ratcliffe, P.J., Cockman, M.E. OGFOD1 catalyzes prolyl hydroxylation of RPS23 and is involved in translation control and stress granule formation. Proc Natl Acad Sci U S A. 2014 Feb 18. [Epub ahead of print]     PubMed

Katz, M.J., Acevedo, J.M., Loenarz, C., Galagovsky, D., Liu-Yi, P., Pérez-Pepe, M., Thalhammer, A., Sekirnik, R., Ge, W., Melani, M., Thomas, M.G., Simonetta, S., Boccaccio, G.L., Schofield, C.J., Cockman, M.E., Ratcliffe, P.J., Wappner, P. Sudestada1, a Drosophila ribosomal prolyl-hydroxylase required for mRNA translation, cell homeostasis, and organ growth. Proc Natl Acad Sci U S A 2014 Feb 18. [Epub ahead of print]     PubMed

Galagovsky, D., Katz, M.J., Acevedo, J.M., Sorianello, E., Glavic, A., Wappner, P. The Drosophila insulin degrading enzyme restricts growth by modulating the PI3K pathway in a cell autonomous manner. Mol Biol Cell 2014 Jan 15. [Epub ahead of print]     PubMed

De Lella Ezcurra, A.L., Bertolin, A.P., Melani, M., Wappner, PRobustness of the hypoxic response: another job for miRNAs? Dev Dyn. 241(12):1842-8 (2012)  Review   PubMed

Perez-Perri, J.I., Acevedo, J.M., Wappner, P. Epigenetics: new questions on the response to hypoxia. Int J Mol Sci. 12(7):4705-21 (2011).  Review  PubMed

Acevedo, J.M.; Centanin, L., Dekanty, A., Wappner, POxygen sensing in Drosophila: multiple isoforms of the prolyl hydroxylase fatiga have different capacity to regulate HIFalpha/Sima. PLoS One 5(8), e12390 (2010).     PubMed

Centanin, L., Gorr, T.A., Wappner, P. Tracheal remodelling in response to hypoxia. J Insect Physiol. 56: 447-454 (2010).     PubMed

Dekanty, A., Romero, N.M., Bertolin, A.P., Thomas, M.G., Leishman, C.C., Perez-Perri, J.I., Boccaccio, G.L.,Wappner, P. Drosophila genome-wide RNAi screen identifies multiple regulators of HIF dependent transcription in hypoxia. PLoS Cenet. 6: e1000994 (2010).     PubMed

Irisarri, M., Lavista-Llanos, S., Romero, N.M., Centanin, L., Dekanty, A., Wappner, P. Central role of the oxygen-dependent degradation domain of Drosophila HIFalpha/Sima in oxygen-dependent nuclear export.  Mol Biol Cell. 20: 3878-3887(2009).     PubMed

Centanin, L., Dekanty, A., Romero, N., Irisarri, M., Gorr, T.A., Wappner, P. Cell autonomy of HIF effects in Drosophila: Tracheal cells sense hypoxia and induce terminal branch sprouting.  Dev Cell. 14: 547-558 (2008).    PubMed

Romero, N.M., Irisarri, M., Roth, P., Cauerhff, A., Samakovlis, C., Wappner, P. Regulation of the Drosophila hypoxia-inducible factor alpha sima by CRM1-dependent nuclear export. Mol Cell Biol. 28: 3410-3423 (2008).    PubMed

Rojas, D.A., Munizaga, D.A., Centanin, L., Antonelli, M., Wappner, P., Allende, M.L., Reyes, A.E. Cloning of hif-1a and hif-2a and mRNA expression pattern during development in zebrafish. Gene Expr Patterns. 7: 339-345 (2007).     PubMed

Romero, N.M., Dekanty, A., Wappner, P. Cellular and developmental adaptations to hypoxia: a Drosophila perspective. Methods Enzymol. 435: 123-144. (2007).   Review PubMed

Gorr, T.A., Gassmann, M., Wappner, P. Sensing and responding to hypoxia via HIF in model invertebrates. J. Insect. Physiol. 52: 349-364 (2006).   Review PubMed

Centanin, L., Ratcliffe, P.J., Wappner, P.  Reversion of lethality and growth defects in Fatiga oxygen-sensor mutant flies by loss of Hypoxia-Inducible Factor-alpha/Sima. EMBO Rep. 6: 1070-1075 (2005).     PubMed

Dekanty, A., Lavista-Llanos, S., Irisarri, M., Oldham, S., Wappner, P.  The insulin-PI3K/TOR pathway induces a HIF-dependent transcriptional response in Drosophila by promoting nuclear localization of HIF-alpha/Sima. J. Cell. Sci. 118: 5431-5441 (2005).     PubMed

Muzzopappa, M., Wappner, P. Multiple roles of the F-box protein Slimb in Drosophila egg chamber development.Development 132: 2561-2571(2005).     PubMed





Pablo Wappner
Head of Laboratory - pwappner@leloir.org.ar



Mariana Melani
Research Associate - mmelani@leloir.org.ar



Maximiliano Katz
Research Associate - mjkatz@leloir.org.ar



Dalmiro Blanco Obregón
Post-doc - dobregon@leloir.org.ar



Lucía Durrieu
Post-doc - ldurrieu@leloir.org.ar



Lautaro Gándara
PhD student - lgandara@leloir.org.ar



Rocío De La Riva Carrasco
PhD student - rvdelarivac@leloir.org.ar



Sebastián Pérez Pandolfo
PhD student - sperezp@leloir.org.ar



Camila Behrensen
Grad student - cbehrensen@leloir.org.ar



Felipe Rodríguez
Grad student - frodriguez@leloir.org.ar



Sofía Suárez
Grad student - ssuarez@leloir.org.ar



Tali Kiperman
Grad student - tkiperman@leloir.org.ar