RBX2 maintains final retinal cell position in a DAB1-dependent and -independent fashion

Development. 2018 Feb 2;145(3):dev155283. doi: 10.1242/dev.155283.

Abstract

The laminated structure of the retina is fundamental for the organization of the synaptic circuitry that translates light input into patterns of action potentials. However, the molecular mechanisms underlying cell migration and layering of the retina are poorly understood. Here, we show that RBX2, a core component of the E3 ubiquitin ligase CRL5, is essential for retinal layering and function. RBX2 regulates the final cell position of rod bipolar cells, cone photoreceptors and Muller glia. Our data indicate that sustained RELN/DAB1 signaling, triggered by depletion of RBX2 or SOCS7 - a CRL5 substrate adaptor known to recruit DAB1 - causes rod bipolar cell misposition. Moreover, whereas SOCS7 also controls Muller glia cell lamination, it is not responsible for cone photoreceptor positioning, suggesting that RBX2, most likely through CRL5 activity, controls other signaling pathways required for proper cone localization. Furthermore, RBX2 depletion reduces the number of ribbon synapses and disrupts cone photoreceptor function. Together, these results uncover RBX2 as a crucial molecular regulator of retina morphogenesis and cone photoreceptor function.

Keywords: CRL5; DAB1; Neuron migration; RBX2; Retina development.

Publication types

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

MeSH terms

  • Animals
  • Cell Adhesion Molecules, Neuronal / metabolism
  • Cell Movement
  • Chromosome Deletion
  • Chromosomes, Human, Pair 3
  • Ependymoglial Cells / cytology
  • Ependymoglial Cells / metabolism
  • Extracellular Matrix Proteins / metabolism
  • Eye Abnormalities / embryology
  • Eye Abnormalities / metabolism
  • Eye Abnormalities / pathology
  • Female
  • Humans
  • Male
  • Mice
  • Mice, 129 Strain
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Nerve Tissue Proteins / deficiency
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Pregnancy
  • Retina / cytology
  • Retina / embryology*
  • Retina / metabolism*
  • Retinal Bipolar Cells / cytology
  • Retinal Bipolar Cells / metabolism
  • Retinal Cone Photoreceptor Cells / cytology
  • Retinal Cone Photoreceptor Cells / metabolism
  • Serine Endopeptidases / metabolism
  • Signal Transduction
  • Suppressor of Cytokine Signaling Proteins / deficiency
  • Suppressor of Cytokine Signaling Proteins / genetics
  • Suppressor of Cytokine Signaling Proteins / metabolism
  • Ubiquitin-Protein Ligases / deficiency
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism*

Substances

  • Cell Adhesion Molecules, Neuronal
  • Dab1 protein, mouse
  • Extracellular Matrix Proteins
  • Nerve Tissue Proteins
  • SOCS7 protein, mouse
  • Suppressor of Cytokine Signaling Proteins
  • Ubiquitin-Protein Ligases
  • Serine Endopeptidases
  • reelin protein