A mass spectrometry-based proteomic analysis of Homer2-interacting proteins in the mouse brain

Abstract

In the brain, the Homer protein family modulates excitatory signal transduction and receptor plasticity through interactions with other proteins in dendritic spines. Homer proteins are implicated in a variety of psychiatric disorders such as schizophrenia and addiction. Since Homers serve as scaffolding proteins, identifying their interaction partners is an important first step in understanding their biological function and could help design novel therapeutic strategies. The present study set out to document Homer2-interacting proteins in the mouse brain using a co-immunoprecipitation-based mass spectrometry approach. Homer2 knockout samples were used to filter out non-specific interactors. We found that in the brain, Homer2 interacts with a limited subset of its previously reported interaction partners (3 out of 31). Importantly, we detected an additional 15 “novel” Homer2-interacting proteins, most of which are part of the N-methyl-D-aspartate receptor signaling pathway. These results corroborate the central role Homer2 plays in glutamatergic transmission and expand the network of proteins potentially contributing to the behavioral abnormalities associated with altered Homer2 expression.

Whole exome sequencing identified a second pathogenic variant in HOMER2 for autosomal dominant non‐syndromic deafness

“…The difference might be due to different functions and roles of the domains where both mutations are located. HOMER2 binds to a number of Ca 2+ ‐handling proteins through its EVH1 domain and multimerizes via the CC domain, resulting in the regulation or facilitation of signal transduction . The c.840_841insC variant lies in the CBD domain within the CC domain, whereas the c.554G>C variant lies only in the CC domain.…”

Homer2 and Alcohol: A Mutual Interaction

“…( 83 ). Recently, “novel” Homer2-interacting proteins have been detected, as part of the signaling cascade that is activated by the glutamatergic transmission, thus expanding the network of proteins that potentially contribute to the behavioral abnormalities associated with alcohol abuse ( 84 , 85 ).…”

Development of Targeted Mass Spectrometry-Based Approaches for Quantitation of Proteins Enriched in the Postsynaptic Density (PSD)

“…Homer proteins self-polymerize and interact with Shank proteins, creating a matrix-like structure [4,24,26]. This scaffolding structure is involved in excitatory signal transduction as well as in receptor plasticity [27]. There are three different Homer genes (1–3) that are differentially expressed throughout the brain [27].…”

“…This scaffolding structure is involved in excitatory signal transduction as well as in receptor plasticity [27]. There are three different Homer genes (1–3) that are differentially expressed throughout the brain [27].…”

“…Synapses differ significantly from one another and can change their composition rapidly, making reproducibility and accuracy of the analysis important [47,48,49,50]. Despite these challenges, researchers have made significant efforts to study the proteome of the PSD, particularly through the use of mass spectrometry [27,42,51,52,53,54,55,56,57,58]. Note, however, that many of the PSD fractionation methods use Triton-X100, a detergent that is not compatible with mass spectrometry analysis.…”