Related Experiment Video
Updated: Apr 18, 2026
Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures
Published on: December 22, 2014
Dysfunction of Unc119, a Transducin-Binding Protein, Leads to Cone-Rod Dystrophy through Activating JAK-Stat and
Koki Kobayashi1, Taro Chaya1, Hung-Ya Tu1
1Laboratory for Molecular and Developmental Biology, Institute for Protein Research, The University of Osaka, Osaka 565-0871, Japan.
Abstract:
Transducin is a heterotrimeric G-protein that is a component of the phototransduction cascade in rod and cone photoreceptor cells of the retina. Gnat1, a rod-specific transducin α-subunit, regulates light/dark adaptation by changing its subcellular localization depending on light. Our previous study revealed that Gnat1 translocation in rod photoreceptor cells under light/dark conditions requires E3 ligase Klhl18-mediated ubiquitination and degradation of Unc119, a Gnat1-binding protein. A mutation in the human UNC119 gene is associated with cone-rod dystrophy (CRD); however, the underlying pathological mechanism remains unclear. In this study, we generated and analyzed Unc119-deficient (Unc119-/- ) mice. We found that the retinas of Unc119-/- mice of both sexes exhibited progressive photoreceptor degeneration, resembling CRD in humans. We also found that Unc119 interacts with Gnat2 in cone photoreceptor cells and that Unc119 is essential for the translocation of Gnat2 to the outer segment in cone photoreceptor cells. RNA-seq and subsequent bioinformatics analysis revealed the predicted activation of the JAK-STAT and NF-κB pathways in the Unc119-/- retina. Treatment of Unc119-/- mice with curcumin, an inhibitor of the JAK-STAT and NF-κB pathways, suppressed inflammation and cone photoreceptor cell degeneration in Unc119-/- retinas. Furthermore, a human CRD-associated UNC119 mutant protein competitively inhibited the interaction between UNC119 and GNAT1 or GNAT2. Taken together, the current study suggests that UNC119 dysfunction leads to CRD by affecting the JAK-STAT and NF-κB pathways and may advance our understanding of the pathological mechanisms of CRD.
Insights
Unc119 protein deficiency causes progressive photoreceptor degeneration, mimicking human cone-rod dystrophy (CRD). This dysfunction activates inflammatory pathways, which can be suppressed by curcumin, offering potential therapeutic insights for CRD.
Area of Science:
- Retinal biology
- Phototransduction
- Neuroscience
Background:
- Transducin (G-protein) is crucial for retinal phototransduction.
- Unc119 protein is a Gnat1-binding protein involved in light/dark adaptation.
- Human UNC119 mutations are linked to cone-rod dystrophy (CRD), but mechanisms are unclear.
Purpose of the Study:
- To investigate the role of Unc119 in photoreceptor function and CRD pathogenesis.
- To elucidate the molecular mechanisms underlying Unc119 deficiency-induced retinal degeneration.
Main Methods:
- Generation and analysis of Unc119-deficient (Unc119-/-) mice.
- Assessment of photoreceptor degeneration and Gnat2 translocation.
- RNA-sequencing and bioinformatics analysis of Unc119-/- retinas.
- Pharmacological inhibition of JAK-STAT and NF-κB pathways using curcumin.
Main Results:
- Unc119-/- mice exhibited progressive photoreceptor degeneration, resembling human CRD.
- Unc119 is essential for Gnat2 translocation in cone photoreceptor cells.
- JAK-STAT and NF-κB pathways were predicted to be activated in Unc119-/- retinas.
- Curcumin treatment suppressed inflammation and photoreceptor degeneration in Unc119-/- mice.
- Human CRD-associated UNC119 mutants interfered with UNC119-GNAT interactions.
Conclusions:
- Unc119 dysfunction leads to CRD by impacting photoreceptor integrity and activating inflammatory pathways (JAK-STAT, NF-κB).
- Targeting these pathways with agents like curcumin may offer therapeutic strategies for CRD.
- This study provides insights into the pathological mechanisms of CRD associated with UNC119 mutations.
