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Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes
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Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes

Published on: January 7, 2013

Surface expression of the netrin receptor UNC5H1 is regulated through a protein kinase C-interacting protein/protein

Megan E Williams1, Sareina C-Y Wu, William L McKenna

  • 1Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064, USA.

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
|December 16, 2003
PubMed

Insights

Neurons control their response to guidance cues like Netrin-1 by regulating surface receptors. Protein Kinase C (PKC) and Protein Interacting with C Kinase-1 (PICK1) control the surface availability of UNC5H1 receptors, modulating axon repulsion.

Area of Science:

  • Neuroscience
  • Cell Biology
  • Molecular Biology

Background:

  • Netrin-1 is a crucial guidance cue for neuronal development, mediating both attraction and repulsion.
  • Axon guidance relies on the precise cell surface expression of receptors like DCC and UNC5H.
  • The mechanisms regulating UNC5H receptor surface expression remain largely unknown.

Purpose of the Study:

  • To investigate the regulation of UNC5H1 receptor surface expression in neurons.
  • To identify proteins involved in controlling UNC5H1 localization and neuronal response to Netrin-1.
  • To elucidate the role of Protein Kinase C (PKC) and Protein Interacting with C Kinase-1 (PICK1) in this process.

Main Methods:

  • Yeast two-hybrid system to identify PICK1 as a UNC5H1 binding partner.
  • Coexpression studies in heterologous cells to observe protein recruitment.
  • Coimmunoprecipitation from cultured hippocampal neurons and P4 cortices.
  • Immunohistochemistry to localize proteins in growth cones.
  • PKC activation assays and assessment of Netrin-1-dependent growth cone collapse.

Main Results:

  • PICK1 binds to the C-terminus of UNC5H1 via its PDZ domain, leading to PICK1 recruitment to UNC5H1 clusters.
  • Endogenous UNC5H1 and PICK1 form complexes in neurons, and are present in growth cones along with PKC.
  • PKC activation promotes the formation of UNC5H1/PICK1/PKC complexes, causing internalization of UNC5H1 from the cell surface.
  • This PKC-dependent reduction in surface UNC5H1 inhibits Netrin-1-induced growth cone repulsion.

Conclusions:

  • Neuronal response to Netrin-1 repulsion is modulated by regulating UNC5H receptor surface expression.
  • PICK1 and PKC play a critical role in controlling UNC5H1 internalization via a PICK1/PKC-dependent mechanism.
  • This provides a novel mechanism for axons to fine-tune their guidance responses during development.

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