Discovery of the Porosome: revealing the molecular mechanism of secretion and membrane fusion in cells
B. P. Jena *
Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, USA
Received: March 19, 2004; Accepted: March 23, 2004
* Correspondence to: Bhanu P. JENA, Ph.D. Department of Physiology, Wayne State University School of Medicine, 5245 Gordon Scott Hall, 540 E. Canfield, Detroit, MI 48201, USA; Tel.: 313-577-1532, Fax: 313-993-4177, E-Mail: bje[email protected]
Secretion and membrane fusion are fundamental cellular processes involved in the physiology of health and disease. Studies within the past decade reveal the molecular mechanism of secretion and membrane fusion in cells. Studies reveal that membrane-bound secretory vesicles dock and fuse at porosomes, which are specialized plasma membrane structures. Swelling of secretory vesicles result in a build-up of intravesicular pressure, which allows expulsion of vesicular contents. The discovery of the porosome, its isolation, its structure and dynamics at nm resolution and in real time, its biochemical composition and functional reconstitution, are discussed. The molecular mechanism of secretory vesicle fusion at the base of porosomes, and vesicle swelling, have been resolved. With these findings a new understanding of cell secretion has emerged and confirmed by a number of laboratories.
Keywords: porosome • cell secretion • membrane fusion • SNAREs • vesicle swelling
Source: J. Cell. Mol. Med. Vol 8, No 1, 2004 pp. 1-21