La exocitosis del espermatozoide
Exocytosis is a key mechanism used by nearly all eukaryotic cells to release a variety of biomolecules, such as peptidic hormones and neurotransmitters, and to insert lipids and proteins into the plasma membrane. The acrosome is a secretory granule released by regulated exocytosis (termed the acros...
Guardado en:
| Autores principales: | , , , , , |
|---|---|
| Publicado: |
2019
|
| Materias: | |
| Acceso en línea: | https://bdigital.uncu.edu.ar/fichas.php?idobjeto=14337 |
| Sumario: | Exocytosis is a key mechanism used by nearly all eukaryotic cells to release a variety of biomolecules, such as peptidic hormones and neurotransmitters, and to insert lipids and proteins into the plasma membrane. The acrosome is a secretory granule released by regulated exocytosis (termed the acrosome reaction) when the sperm meets the egg or in response to stimuli in vitro. In all systems, exocytosis proceeds through a sequence of events governed by complex signal transduction cascades. Such events include the attachment of the secretory vesicle to the plasma membrane and culminate with the opening of a fusion pore between the two bilayers. The late stages require a highly conserved proteinaceous fusion machinery that includes members of the Rab and SNARE superfamilies and their interacting proteins. Rabs are small GTPases whose exocytic isoforms belong to the Rab3 and Rab27 families. SNAREs assemble in highly stable complexes that behave as molecular bridges that initiate fusion by pulling the membranes toward each other. There are several families of exocytotic SNAREs. Both Rabs and SNAREs are essential for the acrosome reaction. The goals of this proposal are to contribute to establish: i) why is the activation of Rab3 by its GEF GRAB necessary but not sufficient to trigger sperm exocytosis, and ii) the mechanism of action of α-synuclein on the exocytotic machinery. We will apply functional assays, electron and fluorescence microscopy as well as in silico, biochemical and molecular biology approaches to deepen our understanding of the molecular mechanisms that drive acrosomal exocytosis. |
|---|
