Distribution of RGS9-2 in neurons of the mouse striatum

J Neurochem. 2010 Feb;112(3):651-61. doi: 10.1111/j.1471-4159.2009.06488.x. Epub 2009 Nov 11.

Abstract

Regulators of G protein signaling (RGS) proteins negatively modulate G protein-coupled receptor (GPCR) signaling activity by accelerating G protein hydrolysis of GTP, hastening pathway shutoff. A wealth of data from cell culture experiments using exogenously expressed proteins indicates that RGS9 and other RGS proteins have the potential to down-regulate a significant number of pathways. We have used an array of biochemical and tissue staining techniques to examine the subcellular localization and membrane binding characteristics of endogenous RGS9-2 and known binding partners in rodent striatum and tissue homogenates. A small fraction of RGS9-2 is present in the soluble cytoplasmic fraction, whereas the majority is present primarily associated with the plasma membrane and structures insoluble in non-ionic detergents that efficiently extract the vast majority of its binding partners, R7BP and G(beta5). It is specifically excluded from the cell nucleus in mouse striatal tissue. In cultured striatal neurons, RGS9-2 is found at extrasynaptic sites primarily along the dendritic shaft near the spine neck. Heterogeneity in RGS9-2 detergent solubility along with its unique subcellular localization suggests that its mechanism of membrane anchoring and localization is complex and likely involves additional proteins beside R7BP. An important nuclear function for RGS9-2 seems unlikely.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Coculture Techniques / methods
  • Corpus Striatum / cytology
  • Corpus Striatum / metabolism*
  • Dopamine and cAMP-Regulated Phosphoprotein 32 / metabolism
  • GTP-Binding Protein beta Subunits / metabolism
  • Glutamate Decarboxylase / metabolism
  • Membrane Microdomains / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microfilament Proteins / metabolism
  • Nerve Tissue Proteins / metabolism
  • Neurons / metabolism
  • Neurons / ultrastructure
  • Protein Binding
  • RGS Proteins / deficiency
  • RGS Proteins / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Subcellular Fractions / metabolism
  • Synapses / metabolism
  • Transcription Factor TFIID / metabolism

Substances

  • Dopamine and cAMP-Regulated Phosphoprotein 32
  • GTP-Binding Protein beta Subunits
  • Microfilament Proteins
  • Nerve Tissue Proteins
  • Ppp1r1b protein, mouse
  • R7BP protein, mouse
  • RGS Proteins
  • Transcription Factor TFIID
  • neurabin
  • regulator of g-protein signaling 9
  • Glutamate Decarboxylase
  • glutamate decarboxylase 2