title: The stealthy nano-machine behind mast cell granule size distribution.
abstract: The classical model of mast cell secretory granule formation suggests that newly synthesized secretory mediators, transported from the rough endoplasmic reticulum to the Golgi complex, undergo post-transitional modification and are packaged for secretion by condensation within membrane-bound granules of unit size. These unit granules may fuse with other granules to form larger granules that reside in the cytoplasm until secreted. A novel stochastic model for mast cell granule growth and elimination (G&E) as well as inventory management is presented. Resorting to a statistical mechanics approach in which SNAP (Soluble NSF Attachment Protein) REceptor (SNARE) components are viewed as interacting particles, the G&E model provides a simple 'nano-machine' of SNARE self-aggregation that can perform granule growth and secretion. Granule stock is maintained as a buffer to meet uncertainty in demand by the extracellular environment and to serve as source of supply during the lead time to produce granules of adaptive content. Experimental work, mathematical calculations, statistical modeling and a rationale for the emergence of nearly last-in, first out inventory management, are discussed.
authors.affiliation: Sackler Faculty of Medicine, Department of Pathology, Tel Aviv University, Tel Aviv 6997801, Israel. Electronic address: ilanh@patholog.tau.ac.il.
authors.forename: Ilan
authors.initials: I
authors.lastname: Hammel
authors.affiliation: Raymond and Beverly Sackler Faculty of Exact Sciences, School of Mathematical Sciences, Department of Statistics and Operations Research, Tel Aviv University, Tel Aviv 6997801, Israel. Electronic address: isaco@math.tau.ac.il.
authors.forename: Isaac
authors.initials: I
authors.lastname: Meilijson
mesh_terms: D000818:Animals; D001692:Biological Transport; D002459:Cell Fusion; D003594:Cytoplasmic Granules / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D015233:Models, Statistical; D051381:Rats; D012397:Rosette Formation; D050600:SNARE Proteins / Q000276:immunology*; D022142:Secretory Vesicles / Q000276:immunology
chemical_list: D050600:SNARE Proteins
keywords: Cellular communication; Homotypic fusion; SNARE; Unit granule