The EH Binding protein EHBP1 operates in a ciliary functional module affected by INPP5E dysfunction.

Area of Science:

• Cell Biology
• Molecular Biology
• Genetics

Background:

• Primary cilia are crucial for cellular function.
• Inositol polyphosphate-5-phosphatase E (INPP5E) is a key ciliary protein.
• Dysfunction of INPP5E is linked to retinal ciliopathies.

Purpose of the Study:

• To identify proteins interacting with INPP5E using proximity labeling.
• To investigate the role of EH binding protein 1 (EHBP1) in primary cilia and photoreceptors.
• To understand the impact of INPP5E dysfunction on EHBP1 localization and retinal ciliopathies.

Main Methods:

• Proximity labeled proteomics of INPP5E.
• Immunofluorescence microscopy in human fibroblasts, RPE cells, and retinal organoids.
• CRISPR/Cas9 gene editing to create INPP5E knock-out models.

Main Results:

• EHBP1 was identified as a ciliary protein localizing to the basal body and ciliary compartment.
• EHBP1 localizes to the outer membrane of developing photoreceptors.
• INPP5E dysfunction alters EHBP1 localization in both patient-derived fibroblasts and knock-out retinal organoids.

Conclusions:

• EHBP1 functions at the primary cilium and photoreceptors and is regulated by INPP5E.
• This interaction provides insights into the pathogenesis of retinal ciliopathies.
• EHBP1 is a potential candidate protein for retinitis pigmentosa and other retinal ciliopathies.