skip to main content

Title: Characterization, localization and function of pertussis toxin-sensitive G proteins in the nervous systems of Aplysia and Loligo

The author has characterized pertussis toxin-sensitive G proteins in the nervous systems of the gastropod mollusc Aplysia and the cephalopod Loligo using ({sup 32}P)ADP-ribosylation and immunoblotting with G protein specific antisera. As in vertebrates, this class of G protein is associated with membranes and enriched in nervous tissue in Aplysia. Analysis of dissected Aplysia ganglia reveal that it is enriched in neuropil, a region containing most of the central nervous system synapses. Because both Aplysia and Loligo synaptosomes are enriched in pertussis toxin-sensitive G proteins, it is likely that they are found in synaptic terminals. Fractionation of Aplysia synaptosomes into membrane and vesicle fractions reveals that, although the majority of G protein is recovered in the plasma membrane fraction, a small proportion is recovered in the vesicle fraction. He shows that G proteins are on intracellular membranes by ADP-ribosylating extruded axoplasm with pertussis toxin. A plausible explanation for vesicular localization of G protein in axoplasm is that G proteins are transported to terminals on vesicles. He has shown, using ligature experiments with Aplysia connectives and temperature block experiments in the giant axon of Loligo, that G proteins move by anterograde fast axonal transport. Injection of pertussis toxin into the identifiedmore » Aplysia neuron L10 blocks histamine-induced presynaptic inhibition of transmitter release. This suggests that pertussis toxin sensitive G proteins play a role in modulating transmitter release at synaptic terminals. In the giant synapse of Loligo, he presents preliminary data that demonstrates that the activation of G proteins in the presynaptic terminal results in decreased transmitter release.« less
Authors:
Publication Date:
OSTI Identifier:
5525342
Resource Type:
Miscellaneous
Resource Relation:
Other Information: Thesis (Ph. D.)
Publisher:
Columbia, NY (US); Columbia Univ.
Research Org:
Columbia Univ., New York, NY (United States)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; MOLLUSCS; NERVOUS SYSTEM; BIOCHEMISTRY; PROTEINS; CHEMICAL COMPOSITION; BIOLOGICAL FUNCTIONS; BIOLOGICAL LOCALIZATION; CELL MEMBRANES; NERVE CELLS; PHOSPHORUS 32; TOXINS; TRACER TECHNIQUES; ANIMAL CELLS; ANIMALS; ANTIGENS; AQUATIC ORGANISMS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CELL CONSTITUENTS; CHEMISTRY; DAYS LIVING RADIOISOTOPES; INVERTEBRATES; ISOTOPE APPLICATIONS; ISOTOPES; LIGHT NUCLEI; MATERIALS; MEMBRANES; NUCLEI; ODD-ODD NUCLEI; ORGANIC COMPOUNDS; PHOSPHORUS ISOTOPES; RADIOISOTOPES; SOMATIC CELLS; TOXIC MATERIALS 551001* -- Physiological Systems-- Tracer Techniques; 550201 -- Biochemistry-- Tracer Techniques