QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Henkel, A. W. Articles by Kornhuber, J. Search for Related Content PubMed PubMed Citation Articles by Henkel, A. W. Articles by Kornhuber, J. Social Bookmarking                         What's this?

A common molecular machinery for exocytosis and the ‘kiss-and-run’ mechanism in chromaffin cells is controlled by phosphorylation

¹ Department of Psychiatry, University of Erlangen, Schwabachanlage 6, 91054 Erlangen, Germany
² Department of Physiology and Neuroscience, New York University Medical Center, MSB 442, 550 First Avenue, NY 10016, USA

View larger version (22K): [in a new window]   Fig. 1. Stimulation-dependent capacitance steps. (A) Im (capacitance) and Re (conductance) traces recorded from a chromaffin cell stimulated with STB/carbachol in the pipette. Several capacitance steps in an upward direction represent fusions of LDCVs. The ‘kiss-and-run’ event in the middle of the trace is magnified and recalculated into vesicle capacitance and pore conductance, according to the formulas shown. (B) Exocytic step frequencies of cells. Black bars, solitary step frequencies; open bars, solitary exocytic flicker step frequencies. All recordings were done in STB except for the controls (SBM). Error bars give the square root of the step count in each bin, scaled to units of frequency. Cells measured: 104 in SBM; 48 at physiological temperature (phys. temp.); 41 in carbachol (Carb); 23 in carbachol plus staurosorine (Carb. +SSP).

View larger version (15K): [in a new window]   Fig. 2. Catecholamine secretion and calcium transients triggered by STB at 35°C. (A) Upper panel: Amperometric recording of catecholamine secretion triggered by elevated temperature in STB. Current spikes represent single catecholamine secretory events. Lower panel: Recording of bath temperature. The bath was warmed from 25°C to 35°C. (B) Intracellular calcium transients recorded from a chromaffin cell in STB at 35°C.

View larger version (15K): [in a new window]   Fig. 3. Flicker pore open times. (A) Capacitance (Cv) and conductance (Gp) traces of a long-duration capacitance flicker from a Staurosporine-pre-treated cell. (B) Open-time histogram of solitary capacitance flickers from cells preincubated with staurosporine.

View larger version (16K): [in a new window]   Fig. 4. Capacitance flicker bursts. (A) Im (capacitance) and Re (conductance) traces recorded during a capacitance burst in STB at 35°C. (B) Im and Re traces recorded in STB/carbachol/ staurosporine at room temperature.

View larger version (17K): [in a new window]   Fig. 5. Percentage of cells with capacitance steps. This graph shows the percentage of cells that showed exocytotic steps. The steps are categorised into three groups: solitary steps, solitary flicker steps and burst steps. STB was present in all stimulation experiments as indicated. Cells measured: 104 in SBM; 48 at physiological temperature (phys. temp.); 41 in carbachol (Carb); 23 in carbachol plus staurosporine (Carb. +SSP).

View larger version (17K): [in a new window]   Fig. 6. Common molecular machinery for transmitter release. (A) The proteolipid pore complex connects to the corresponding pore protein array in the plasma membrane; (B) calcium triggers a conformational change in the protein array and the ring structure opens; (C) the ring remains in a meta-stable open-confirmation, that is, it can widen and constrict rapidly (flickering); (D) eventually the pore closes; (E) the vesicle leaves the docking site; (F) the pore dilates, and the vesicle fuses with the plasma membrane (complete exocytosis); (G) the vesicle is retrieved by dynamin-clathrin-dependent endocytosis.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

Twitter