Identification of new structural elements within ‘porosomes’ of the exocrine pancreas: A detailed study using high-resolution electron microscopy

Neuronal porosome – The secretory portal at the nerve terminal: Its structure–function, composition, and reconstitution

“…Our studies and studies from other laboratories (Craciun and Barbu-Toduran, 2013; Elshennay, 2011; Hammel and Meilijson, 2012; Japaridze et al, 2012; Matsuno et al, 2008; Okuneva et al, 2012; Paredes-Santos et al, 2012; Savigny et al, 2007; Siksou et al, 2007) established porosomes to be secretory portals that perform the specialized task of fractional discharge of intravesicular contents from cells during cell secretion. The significance of the porosome discovery is reflected by several publications involving its structure (Craciun and Barbu-Toduran, 2013; Elshennay, 2011; Hammel and Meilijson, 2012; Japaridze et al, 2012; Matsuno et al, 2008; Okuneva et al, 2012; Paredes-Santos et al, 2012; Savrgny et al, 2007; Siksou et al, 2007), and the associated transient fusion mechanism (Aravanis et al, 2003; Taraska et al, 2003; Thorn et al, 2004) accompanied by fractional discharge of intravesicular contents from cells. Studies in endocrine cells report secretory granules to be recaptured largely intact following stimulated exocytosis (Taraska et al, 2003); in neurons, single synaptic vesicles fuse transiently and successively without loss of vesicle identity (Aravanis et al, 2003); and in the exocrine pancreas, secretion is characterized by long fusion pore openings and preservation of secretory vesicle lipid identity (Thorn et al, 2004).…”

Atomic force microscopy: High resolution dynamic imaging of cellular and molecular structure in health and disease

“…Subsequently, the porosome has been demonstrated to be present in every cell type thus far examined, including endocrine cells and neurons (Fig. ) (Cho et al, ; Jena et al, ; Jeremic et al, ; Siksou et al, ; Zhao et al, ; Drescher et al, ; Elshennawy, ; Craciun and Barbu‐Tudoran, ; Japaridze et al, ; Lee et al, ; Okuneva et al, ). These studies have demonstrated that secretory vesicles “transiently” dock and fuse at the base of the porosome complex to release their contents to the outside milieu of the cell, a concept supported by other investigations of cell secretion and synaptic transmission (Aravanis et al, ; Taraska et al, ; Thorn et al, ).…”

Porosome: a membrane microdomain acting as the universal secretory portal in exocytosis

“…Although the discovery of porosomes was facilitated by AFM, images of these structures have also been captured with conventional electron microscopy 16,29,30 . This confirmed the cup-shaped architecture of the porosome, but these studies also offered some new insights.…”