Instituto/Facultad

IHEM - CONICET - Facultad de Ciencia Médicas - Universidad Nacional de Cuyo (National University of Cuyo, Medical School )

8pCPT induced [Ca 2+] i increase in human sperm

S1P induced [Ca 2+] i increase in human sperm

Caenorhabditis elegans  spermatids were activated with proteases.

Visualization of acrosomal reaction in real time.

Research interest

Sperm have a single opportunity to fertilize an egg; hence they must release the content of their secretory granule (the acrosome) at the right time and place. We postulate that in resting sperm, the factors that participate in exocytosis are maintained in an inactive state. For example, SNAREs are assembled in cis complexes whereas NSF and synaptotagmin are inactivated by phosphorylation. Our interest is to characterize the mechanisms by which the exocytic process is maintained in hold in resting sperm, and the series of events that modify the morphology and the biochemical machinery of the acrosome to trigger the release of hybrid vesicles together with the granule content upon stimulation. Our strategy is to use a combination of the following approaches: i) a well-characterized exocytosis assay developed in SLO-permeabilized human sperm , ii) the use of polyR-modified membrane permeant proteins, iii) electron microscopy, iv) real time imaging, and v) mathematical modeling.

Principal Investigator

Luis S. Mayorga

Contact information

Phone: 54-261-4494143, extension: 2744

Fax: 54-261-4494117

lmayorga@fcm.uncu.edu.ar

Members

Dr. Luis Mayorga (Principal Investigator CONICET, Associate Professor, Biological Chemistry, FCM)

Dr. Martín Zoppino (Postdoctoral fellowship, CONICET, Teaching Assistant, FCM)

Dr. Martín Pavarotti (Postdoctoral fellowship, CONICET, Teaching Assistant, FCM)

Dr. Jimena Castillo (Postdoctoral fellowship, CONICET, Teaching Assistant, FCM)

Lic. Biología Molecular Oscar Bello (Doctoral fellowship, CONICET)

Lic. Biología Molecular Cristian Pocognoni (Doctoral fellowship, CONICET)

Technicians

Marcelo Furlán (Technician CONICET)

Alejandra Medero (Technician CONICET)

Graciela Gutiérrez (Secretariat FCM)

Recent publications

•  De Blas, G.A., Roggero, C.M., Tomes, C.N., and Mayorga, L.S. (2005) Dynamics of SNARE assembly and disassembly during sperm acrosomal exocytosis. PLoS Biology. 3, e323 (1801-1812)

•  Branham, M.T., Mayorga, L.S. and Tomes, C.N. (2006) Calcium-induced acrosomal exocytosis requires cAMP acting through a PKA-independent, EPAC-mediated pathway. J. Biol. Chem. 281, 8656-8666

•  Magadán, J.G., Barbieri, M.A., Mesa , R., Stahl, P.D., and Mayorga, L.S. (2006) Rab22a regulates the sorting of transferrin to recycling endosomes. Mol. Cell. Biology 26, 2595-2614.

•  Real, S.M., Marzese, D.M., Gómez, L.C., Mayorga, L.S., and Roqué, M. (2006) Development of a Premature Stop Codon-detection method based on a bacterial two hybrid system. BMC Biotechnology 6, 38. doi:10.1186/1472-6750-6-38

•  Lopez, C.I., Belmonte, S.A., De Blas, G.A., and Mayorga, L.S. (2007) Membrane-permeant Rab3A triggers acrosomal exocytosis in living human sperm. FASEB J. 21 , 4121-4130.

•  Gomez, L.C., Real, S.M, Ojeda, M.S., Sergio Jiménez, S., Mayorga, L.S., and Roqué, M. (2007) Polymorphism of the FABP2 gene: a population frequency analysis and an association study with Cardiovascular Risk Markers in Argentina . BMC Medical Genetics. 8, 9.

•  Roggero, C. M., De Blas, G., A., Dai, H., Tomes, C, N., Rizo, J., Mayorga, L. S. (2007) Complexin/synaptotagmin interplay controls acrosomal exocytosis. J. Biol. Chem. 282, 26335-26343.

•  Jordao, L., Bleck, C.K.E., Mayorga, L., Griffiths , G., and Anes, E. (2008) On the killing of mycobacteria by macrophages. Cellular Microbiology. 10, 529-48

•  Kühnel, M., Mayorga, L.S., Dandekar, T., Tacar, J., Schwarz, R., Anes, E., Griffiths, G., and Reich. J. (2008) Modelling phagosomal lipid networks that regulate actin assembly. BMC Systems Biology, 2 , 107. Corresponding autor and equal contribution with Kühnel.

•  Bátiz, L.F., De Blas, G.A., Michaut, M.A., Ramírez, A.R, Rodríguez, F., Ratto, M.H., Oliver, C, Tomes, C.N., Rodríguez, E.M., and Mayorga, L.S. (2009) Sperm from hyh mice carrying a point mutation in a SNAP have a defect in acrosome reaction. PloS ONE, 4, e4963

•  Zarelli, V.E.P, Ruete, M.C., Roggero, C.M., Mayorga, L.S., and Tomes, C.N. (2009) PTP1B dephosphorylates NSF and elicits SNARE complex disassembly during human sperm exocytosis. J. Biol. Chem., 284: 10491-10503

•  Zanetti, N., and Mayorga, L.S. (2009) Acrosomal swelling and membrane docking are required for hybrid vesicle formation during the human sperm acrosome reaction. Biol. Reprod. 81, 396-405

Branham MT, Bustos MA, De Blas GA, Rehmann H, Zarelli VE, Trevino CL, Darszon A, Mayorga LS, Tomes CN. (2009) Epac activates the small G proteins Rap1 and Rab3A to achieve exocytosis. J. Biol. Chem, 284, 24825-24839.

Suhaiman L, De Blas GA, Obeid LM, Darszon A,  Mayorga LS, and Belmonte SA (2010) Sphingosine 1-phosphate and sphingosine kinase are involved in a novel signaling pathway leading to acrosomal exocytosis. J. Biol. Chem, 285, 16302-16314.

Mayorga LS, Campoy EM (2010) Modeling fusion/fission-dependent intracellular transport of fluid phase markers.  Traffic 11, 1001-1015.

Castillo Bennett J, Roggero CM, Mancifesta FE, and Mayorga LS (2010) Calcineurin-mediated dephosphorylation of synaptotagmin VI is necessary for acrosomal exocytosis. J. Biol. Chem, 285, 26269-26278.

Present support

- Cambios morfológicos y moleculares que median la exocitosis MINCyT, ANPCyT PICT-2008-1114. acrosomal.  Director.

- Bases Morfológicas y Bioquímicas de la Exocitosis Acromosal. UNCuyo. 06/J319 2009-2011. Director.

- Exocitosis regulada y fertilización. MINCyT, CONICET. PIP 112-200801-02277. 2009-2011.

Internal collaborations

Our laboratory works in close collaboration with groups in the IHEM leaded by

Claudia Tomes

Silvia Belmonte

Marcela Michaut.

International collaborations

Our laboratory works in close collaboration with groups in the IHEM leaded by

Claudia Tomes

Silvia Belmonte

Marcela Michaut.

International collaborations

Alberto Darszon : Universidad Nacional Autónoma de Mexico , Mexico

Teaching activity

The members of the Laboratory are involved in the following courses

De las Moléculas a las Células (From Molecules to the Cell). For undergraduate students, Medical School .

Termodinámica Molecular (Molecular Thermodynamics). Open course

Curso de verano Biología Celular y Molecular (summer course of Cell and Molecular Biology). Undergraduate students, Medical School

Biología Celular y Molecular (Cell and Molecular Biology). Graduate student. Biology Doctoral Program (PROBIOL)

Thesis completed in the Laboratory

2006-2011      Jimena Castillo Bennett.  Médica UNCuyo. PROBIOL. Beca Estensoro de la Fundación YPF y CONICET2008. Tema:  La fosforilación de sinaptotagmina y la dinámica del citoesqueleto de actina regulan la exocitosis acrosomal en espermatozoides humanos.  Aprobada (sobresaliente).

2004-2010      Natalia Zanetti.  Licenciada en Biología Molecular. PROBIOL. Tema: Aspectos morfológicos y funcionales de la exocitosis acrosomal. Beca ANPCYT. Aprobada (sobresaliente).

2003-2009      Cecilia López, Lic. Biología Molecular de la UNSL.  PROBIOL.  Tema: Mecanismos moleculares involucrados en la exocitosis acrosomal del espermatozoide humano. Aprobada (sobresaliente)

2002-2008 Marcelo Roggero, Lic. Biología Molecular de la UNSL. Doctorado Fac. de Farmacia y Bioquímica, Universidad de Buenos Aires. Tema "Papel de la proteína sensora de calcio sinaptotagmina 6 en la exocitosis acrosomal de espermatozoides humanos". Aprobada (sobresaliente).

2002-2006 Javier Magadán, Lic. en Biología Molecular de la UNSL. Doctorado Fac. de Farmacia y Bioquímica, Universidad de Buenos Aires. Tema: Rol funcional de la pequeña GTPasa Rab22a en la regulación de los procesos de endocitosis y reciclaje del receptor de transferrina hacia la membrana celular". Aprobada (sobresaliente)

2006 Gerardo De Blas, Bioquímico de la UJAM. Doctorado UN. Córdoba. Facultad de Ciencias. Mecanismo molecular de la exocitosis acrosomal en espermatozoides humanos. Sobresaliente.

2003 Nora Arenas. Profesora de Biología. Instituto San Pedro Nolasco Transporte intracelular de Brucella abortus en macrófagos. Programa de Postgrado en Biología. U.N. de Cuyo. Sobresaliente.

2003 Rosana Mesa , Bioquímica, UNSan Luis: Transporte endocítico en células que sobreexpresan Rab22. Doctorado en Bioquímica de la Fac. Qca. Bioqca y Facia, UNSan Luis. Sobresaliente.

2003 María Roqué, Bióloga UBA. Desarrollo de métodos moleculares para el diagnóstico de enfermedades hereditarias. Programa de Postgrado en Biología. U.N. Cuyo. Sobresaliente.

2002 Eduardo Pusiol. Lic. en Bioquímica, UNSan Luis. Tema: Métodos bioquímicos para el diagnóstico y seguimiento de cáncer de tiroides. Doctorado en Bioquímica. Fac. Qca. Bioqca y Fcia. U.N. de San Luis. Sobresaliente.

2001 Marcela Michaut, Lic. en Bioquímica, UNSan Luis. Tema: Mecanismo de fusión de membranas durante la reacción acrosomal de espermatozoides humanos. Doctorado en Bioquímica. Fac. Qca. Bioqca y Fcia. U.N. de San Luis. Sobresaliente con mención.

1998 Alejandro Aballay, Farmacéutico, Univ. Juan Agustin Maza. Mecanismo de fusión de membranas en la vía endocítica. Programa de Postgrado en Biología. U.N. Cuyo. Sobresaliente.

1998 Luis Domínguez, Lic. en Biología, UN Mar del Plata. Mecanismo molecular de la transducción de señales en la reacción acrosomal del espermatozoide humano: participación de proteínas G, calcio y fosfolipasa A2. Programa de Postgrado en Biología. U.N. Cuyo. Sobresaliente.

Actualizado Abril 2011