Avtor/Urednik		Guček, Alenka; Jorgačevski, Jernej; Górska, Urszula; Rituper, Boštjan; Kreft, Marko; Zorec, Robert
Naslov		Local electrostatic interactions determine the diameter of fusion pores
Tip		članek
Vol. in št.		Letnik 9, št. 2
Leto izdaje		2015
Obseg		str. 96-101
ISSN		1933-6950 - Channels (Austin, Tex.)
Jezik		eng
Abstrakt		In regulated exocytosis vesicular and plasma membranes merge to form a fusion pore in response to stimulation. The nonselective cation HCN channels are involved in the regulation of unitary exocytotic events by at least two mechanisms. They can affect SNARE-dependent exocytotic activity indirectly, via the modulation of free intracellular calcium; and/or directly, by altering local cation concentration, which affects fusion pore geometry likely via electrostatic interactions. By monitoring membrane capacitance, we investigated how extracellular cation concentration affects fusion pore diameter in pituitary cells and astrocytes. At low extracellular divalent cation levels predominantly transient fusion events with widely open fusion pores were detected. However, fusion events with predominately narrow fusion pores were present at elevated levels of extracellular trivalent cations. These results show that electrostatic interactions likely help determine the stability of discrete fusion pore states by affecting fusion pore membrane composition.
Proste vsebinske oznake		electrostatic interactions fusion pore exocytosis elektrostatične interakcije fuzijska pora eksocitoza