Members

Principal Investigator

Jimena Sierralta
Biochemist. Pontificia Universidad Católica de Chile,PhD in Biological Sciences, Universidad de Chile.

Associate Professor, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile (www.icbm.cl).

Principal Investigator Millenium Biomedical Neuroscience Institute (www.bni.cl)

Graduate Students

César Astorga
Ph.D. candidate. Program in Biomedical Sciences, Faculty of Medicine, Universidad de Chile.

The DLG-MAGUK subfamily of proteins play a role in the structure and function of the synapse. discs-large (dlg) is the only gene of this subfamily in the Drosophila genome, originating two main protein products, DLGA and DLGS97 differing by the inclusion of an L27 domain in DLGS97.

Evidence in mammals suggests postsynaptic functions on the recycling and clustering of glutamate receptors. In Drosophila there is no evidence of a direct link between DLG and glutamate receptors clustering. I am studying the contribution of DLGA and DLGS97 to the basal function and plasticity of the synapses in the Drosophila larval neuromuscular junction.

For this, I use specific mutants of dlgS97 and dlgA and record, from muscles of third instar larvae, the postsynaptic currents under voltage-clamp during spontaneous activity and under low and high frequency stimulation. I will also apply imaging techniques to study the vesicle recycling and the calcium dynamics in these mutants.

María Graciela Delgado
PhD student. Program in Biomedical Sciences, Faculty of Medicine, Universidad de Chile. Huntington’s disease (HD) is a neurodegenerative disorder characterized by adult-onset of motor dysfunctions, psychiatric disturbances and intellectual decline. This fatal inherited autosomal dominant pathology is associated with an unstable CAG (Gluthamine codon) expansion in the huntingtin gene on chromosome 4.

Recently, signs of endoplasmic reticulum stress have been reported in animal models of HD, probably due to the activation of the unfolded protein response (UPR) during the disease pathogeny.

In this project, we are interested in studying the functional contribution of UPR proteins to HD progression. Currently we are using flies that selectively express human Huntingtin protein in the fly eye. Taking advantage of the UAS-Gal 4 expression system, we have successfully silenced key proteins involved in the UPR; XBP-1 (UPR transcription factor), IRE 1α (transmembrane inositol requiring kinase/endonuclease) and BOK (fly homologue of BCL-2 protein). The functional and structural assessment of these transgenic lines is performed with electrophysiology, molecular biology and light microscopy techniques. This work is being carried out in collaboration with Dr. Claudio Hetz laboratory.

Cristian de Gregorio
Ph.D. student Program in Biomedical Sciences, Faculty of Medicine, Universidad de Chile.

My work is related to the study of the protein Atlastin, a small GTPase involved in the morphogenesis of the endoplasmic reticulum that has remained conserved through evolution from invertebrates to mammals. Mutations in this protein produces in humans a disease called spastic hereditary paraplegia, characterized by the degeneration of the axons of the motorneurons and muscular spasticity.

I am interested in dilucidate the function of Atlastin as a morphogen of the endoplasmic reticulum and function of neurons and muscles. We will use a Drosophila in vivo model of Altastin loss of function and look for disturbance of the traffic and destination of the proteins to the synapse. This work is being carried out in collaboration with Dr. Andrés Couve laboratory.

José Cánovas
Ph.D. student, Program in Cellular and molecular biology and neuroscience. Faculty of Science, Universidad de Chile.

The transcription factor, CTIP1 was identified in a Drosophila screen for genes involved in neuronal morphogenesis. I am studying its role in the development of the mammalian brain cortex using as model the mouse. Our results are compatible with a role of CTIP1 in the specification of subclasses of projection neurons in the cerebral cortex. This work is being carried as a collaboration between Dr. Manuel Kukuljan laboratory and J. Sierralta`s lab.

Claudia Molina
Graduate thesis Ms Program in Genetics, Faculty of Medicine

Undergraduate Students

Pía Escobedo
Undergraduate thesis, Biochemistry, Universidad de Valparaíso.

My undergraduate thesis has been focus in the interaction between two MAGUK proteins, DLG and CASK and the role of this interaction in the localization and activity of CASK, and CAMKII as a key protein involved in synaptic plasticity.

For this I have studied the subcellular localization and abundance of CAMKII and CASK in the neuromuscular junction of third instar WT and dlg mutant Drosophila larvae.

Guillermo Moya
Undergraduate thesis student (USACH).

My undergraduate thesis is focus in the function of NMDAR in the synaptic function and plasticity of the neuromuscular junction of Drosophila larvae.

To study this we are using electrophysiological (Voltage Clamp) and image analysis technics applied to WT and mutant animals.

Mauricio Ramírez
Undergraduate thesis (PUCV).

My undergraduate thesis is centered on the development of an standarized analyses of confocal images to quantify the number and size of the glutamate receptors clusters in the neuromuscular junction of the Drosphila larvae.

I will apply then the procedure to study these parameters in mutants of synaptic proteins to determine the role of these proteins in the synapse function.

Ronald Pérez
Undergraduate thesis, Medical Technology, Faculty of Medicine

Professionals

Estefanía López
Engineer in Biotechnology, Ms in Cellular and molecular biology.

My main project is related with the validation of targets of the transcription factor Hindsight (Oliva and Sierralta, 2010). This work is been carried out in colaboration with Dr. Patricio Olguín (Program of Human Genetics, Facultad de Medicina, Universidad de Chile) and Dr. Carlos Oliva (University of Leuven)

Technicians Fly Room

Pablo Vélis
Fabián Yañez
Jonathan Henríquez
Patricio Pezo

General Lab Assistants

Angélica Figueroa
Fernando Vergara
Inés Contreras

More:  Past members