Occurrence of the alpha subunits of G proteins in cerebral cortex synaptic membrane and postsynaptic density fractions: modulation of ADP-ribosylation by Ca2+/calmodulin.

Abstract

We have examined the isolated postsynaptic density (PSD) Pertussis Toxin-Activated ADP-Ribosylation. Pertussis toxin-activated ADP-ribosylation of SM and PSD proteins was performed as described using [32P]NADP (35). The samples were processed by SDS/PAGE and autoradiography (36), with the polyacrylamide gel being a 7.5-15% linear gradient in all cases. MATERIALS AND METHODS Materials. Guanosine 5'-[-[35S]thio]triphosphate (GTP[-35S]) (1400Immunochemical Characterization of the G Proteins. To identify the G proteins in the SM and PSD fractions, the subcellular fractions (60 ,ug each) were subjected to SDS/ PAGE and the resolved proteins in the gel were transferred electrophoretically to Immobilon (Millipore) paper as described (37). The Western blot blots were probed with anti-Ga antibodies followed by 125I-labeled protein A (38). 8686The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Hyperdopaminergic Tone Erodes Prefrontal Long-Term Potential via a D2Receptor-Operated Protein Phosphatase Gate

“…The D2 dominance in this synapse may reflect a more enriched representation of the signaling component(s) within D2-coupled signaling cascades. For instance, Giα, a G protein subunit that inhibits adenylyl cyclase, is considerably more abundant than the adenylyl cyclase-stimulating Goα, in cortical postsynaptic densities (Wu et al, 1992). Alternatively, a compartmentalized, D2-specific signaling system tightly coupled to the LTP induction machinery in the synapse may account for the D2 dominance.…”

Molecular constituents and phosphorylation‐dependent regulation of the post‐synaptic density

“…ErbB, a receptor tyrosine kinase, is a neurelin receptor and is localized at the PSD (Huang et al, 2001). Neuregulin is known as an Penzes et al (2000) Gi2a (41 kDa), Gq2a (39 kDa) Wu et al (1992) (Continued ) Walikonis et al (2000) essential factor for synapse-specific transcription of the acetylcholin receptor gene at the neuromuscular junction.…”

Dendritic Spines: Cellular Specializations Imparting Both Stability and Flexibility to Synaptic Function

“…The plasma membrane also contains many integral proteins, of which some are specific to the synapse and others are generally found throughout the neuron. For example, two G proteins (G i & Go) that are involved in the opening of Ca 2+ and K + channels are found in the synaptic plasma membrane fraction (Wu et al 1992). Although the composition of the synaptic cleft has not yet been delineated, it is likely comprised of cell surface molecules involved in cell-cell adhesion (McDonald 1989, Akiyama et al 1990.…”