Vesicles cell-vesicle fusion

Bonifacino JS, Glick BS (2004) The mechanisms of vesicle budding and fusion. Cell 116 153-166... 

In the central nervous system (CNS) the concept that localized microdomains of calcium are responsible for triggering vesicle fusion generally refers to neurons (Rizzuto and Pozzan 2006). Concerning glial cells although the existence of structural... 

Gruenberg J, Griffiths G, Howell KE. Characterization of the early endosome and putative endocytic carrier vesicles in vivo and with an assay of vesicle fusion in vitro. J Cell Biol 1989 108(4) 1301-1316. 

Transcytosis (vesicular transport, C). When new vesicles are pinched off, substances dissolved in the extracellular fluid are engulfed, and then ferried through the cytoplasm, vesicles (phagosomes) undergo fusion with lysosomes to form phagolysosomes, and the transported substance is metabolized. Alternatively, the vesicle may fuse with the opposite cell membrane (cytopempsis). 

VLDLs, IDLs, and LDLs are closely related to one another. VLDLs formed in the liver (see p. 312) transport triacylglycerols, cholesterol, and phospholipids to other tissues. Like chylomicrons, they are gradually converted into IDL and LDL under the influence of lipoprotein lipase [1]. This process is also stimulated by HDL. Cells that have a demand for cholesterol bind LDL through an interaction between their LDL receptor and ApoB-100, and then take up the complete particle through receptor-mediated endocytosis. This type of transport is mediated by depressions in the membrane ( coated pits"), the interior of which is lined with the protein clathrin. After LDL binding, clathrin promotes invagination of the pits and pinching off of vesicles ( coated vesicles"). The clathrin then dissociates off and is reused. After fusion of the vesicle with ly-sosomes, the LDL particles are broken down (see p. 234), and cholesterol and other lipids are used by the cells. 

Rizo J, Chen X, Arac D (2006) Unraveling the mechanisms of synaptotagmin and SNARE function in neurotransmitter release. Trends Cell Biol 16 339-50 Rizo J, Sudhof TC (2002) Snares and Muncl8 in synaptic vesicle fusion. Nat Rev Neurosci 3 641-53... 

Haruta T, Takami N, Ohmura M et al (1997) Ca2+-dependent interaction of the growth-associated protein GAP-43 with the synaptic core complex. Biochem J 325 455-63 Harvey VL, Stephens GJ (2004) Mechanism of GABA receptor-mediated inhibition of spontaneous GABA release onto cerebellar Purkinje cells. Eur J Neurosci 20 684-700 Hata Y, Slaughter CA, Siidhof TC (1993) Synaptic vesicle fusion complex contains unc-18 homo-logue bound to syntaxin. Nature. 366 347-51... 

Lonart G, Schoch S, KaeserPS et al (2003) Phosphorylation of RIMlalphaby PKA triggers presynaptic long-term potentiation at cerebellar parallel fiber synapses. Cell 115 49-60 Lou X, Scheuss V, Schneggenburger R (2005) Allosteric modulation of the presynaptic Ca2+ sensor for vesicle fusion. Nature 435 497-501... 

Petrucci TC, Macioce P, Paggi P (1991) Axonal transport kinetics and posttranslational modification of synapsin I in mouse retinal ganglion cells. J Neurosci 11 2938 16 Pevsner J, Scheller RH (1994) Mechanisms of vesicle docking and fusion insights from the nervous system. Curr Opin Cell Biol 6 555-60... 

Samuels, A. L. and Staehelin, L. A. 1996. Caffeine inhibits cell plate formation by disrupting membrane reorganization just after the vesicle fusion step. Protoplasma 195, 144-155... 

Although not as acidic as lysosomes (with an intra-compartmental pH of 4.5, see Ref. 21), the pH 5.5 environment of the endosome [22] is sufficiently low to cause the dissociation of some hormones from their receptors. When this occurs, there is a subsequent sequestering of the free hormone from the receptor in a related vesicle and tubule compartment called CURL (compartment for uncoupling of receptor from ligand, see Ref. 23), where the free hormone is sequestered into the vesicular structure while the receptor accumulates in the membrane of the tubule structure. A subsequent physical separation of these compartments allows for the differential processing of the hormone versus the receptor. Thus, while the free hormone is ultimately delivered (via vesicle fusion) to the lysosome where it is degraded, the free receptor may be recycled (via the Golgi compartment) to the cell... 

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