ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: A rat pheochromocytoma (PC12) cell line was used to examine the possibility that 5-hydroxytryptamine (serotonin), 3,4-dihydroxyphenylethylamine (dopamine), or noradrenaline may be associated with cytoplasmic actin, as was suggested by previous in vitro binding studies on an actin-like protein from rat brain synaptosomes. When PC12 cells were incubated with [3H]serotonin, [3H]dopamine, or [3H]noradrenaline for 30 min at 37°C, approximately 2–4% of the radioactivity present in the cells was found to be associated with a high-molecular-weight (actin-like) component in supernatant fractions. Evidence relating this monoamine binding component to actin filaments includes: (a) its strong absorption by myosin filaments at low ionic strength; (b) a decrease in its affinity for myosin in the presence of 1 mM ATP, which lowers the affinity of authentic actin for myosin; (c) displacement of bound [3H]serotonin from it by DNase I, which binds strongly to actin and which inhibits [3H]serotonin binding to actin in vitro; (d) an increase in its binding of each monoamine (by 25–40%) after PC12 cells were preincubated with 10 μM cytochalasin B (a drug that induces depolymerization of F-actin). These findings suggest that serotonin, dopamine, or noradrenaline may associate with actin filaments in vivo.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1985.tb04068.x
