First identification of ITM2B interactome in the human retina

ABSTRACT: ITM2B is a type II ubiquitous transmembrane protein which role remains unclear. ITM2B mutations have been associated with different disorders: mutations leading to longer mutant proteins have been reported in two distinct Alzheimer-like autosomal dominant disorders with early-onset progressive dementia, cerebellar ataxia, spasticity and variable degrees of deafness, early onset-cataract and vascular retinal abnormalities. Both disorders share neurological features including severe cerebral amyloid angiopathy, non-neuritic plaques, and fibrillary tangles as in Alzheimer Disease. Our group reported a missense mutation in ITM2B underlying an unusual retinal dystrophy with no dementia. This finding would suggest a specific role of ITM2B in the retina. The identification and characterization of retinal protein partners would bring new insights to the cellular functions of ITM2B in the retina. We performed ITM2B immunoprecipitation followed by quantitative proteomic analysis on normal human retina using two distinct antibodies recognizing different epitopes of the protein. Two pools of ITM2B protein partners were identified for each antibody and compared for functional annotation. Besides common proteins, specific partners involved in translation and mitochondrial homeostasis were identified suggesting a role of ITM2B in these cellular functions. To our knowledge, this is the first report of ITM2B interactome in human retina. Our findings also support a unique and specific role for the newly annotated ITM2B protein isoform.

INSTRUMENT(S): Exactive Plus

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Retina

SUBMITTER: Thibaut LEGER  

LAB HEAD: Isabelle Audo

PROVIDER: PXD020088 | Pride | 2021-09-09

REPOSITORIES: Pride