Cholesterol Alters the Dynamics of Release in Protein Independent Cell Models for Exocytosis
Artikel i vetenskaplig tidskrift, 2016

Neurons communicate via an essential process called exocytosis. Cholesterol, an abundant lipid in both secretory vesicles and cell plasma membrane can affect this process. In this study, amperometric recordings of vesicular dopamine release from two different artificial cell models created from a giant unilamellar liposome and a bleb cell plasma membrane, show that with higher membrane cholesterol the kinetics for vesicular release are decelerated in a concentration dependent manner. This reduction in exocytotic speed was consistent for two observed modes of exocytosis, full and partial release. Partial release events, which only occurred in the bleb cell model due to the higher tension in the system, exhibited amperometric spikes with three distinct shapes. In addition to the classic transient, some spikes displayed a current ramp or plateau following the maximum peak current. These post spike features represent neurotransmitter release from a dilated pore before constriction and show that enhancing membrane rigidity via cholesterol adds resistance to a dilated pore to re-close. This implies that the cholesterol dependent biophysical properties of the membrane directly affect the exocytosis kinetics and that membrane tension along with membrane rigidity can influence the fusion pore dynamics and stabilization which is central to regulation of neurochemical release.

membrane tension

snare proteins

individual chromaffin cells

hemifusion

lipid nanotubes

vesicles

bending elasticity

kiss-and-run

flickering fusion pores

pc12 cells

Författare

Neda Najafinobar

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Analytisk kemi

Lisa Mellander

Göteborgs universitet

Michael Kurczy

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Analytisk kemi

Johan Dunevall

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Analytisk kemi

Tina B. Angerer

Göteborgs universitet

John Fletcher

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Analytisk kemi

Ann-Sofie Cans

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Analytisk kemi

Scientific Reports

2045-2322 (ISSN)

Vol. 6 33702

Ämneskategorier

Kemi

DOI

10.1038/srep33702

PubMed

27650365