Back

A Catalytically Inactive Protein Kinase C alpha Mutation Drives Chordoid Glioma by Pathway Rewiring

Bellamy, C.; Tovell, H.; Schwaighofer, S.; Baffi, T.; Arslan, J.; Letourneur, Q.; Dingli, F.; Loew, D.; Kornev, A.; Lerond, J.; Kao, T.; Liva, S.; Izac, B.; Andrieu, M.; Adle-Biassette, H.; Barnier, J.-V.; Stefan, E.; Sanson, M.; Newton, A.; Bielle, F.

2025-05-31 molecular biology
10.1101/2025.05.30.657104 bioRxiv
Show abstract

Abstract SummaryChordoid glioma (ChG) is a rare, low-grade brain tumor characterized by a novel recurrent point mutation, D463H, in the kinase domain of protein kinase C alpha (PKC). The mutation is invariably an Asp to His substitution, suggesting it endows a unique function beyond catalytic inactivation associated with other cancer-associated PKC mutations. Here we use in vitro and in cellulo activity assays to show that PKCD463H is catalytically inactive, functions as a dominant-negative mutant to suppress endogenous PKC and uniquely rewires the cellular interactome. Specifically, phosphoproteomic, proximity labeling, and co-immunoprecipitation mass-spectrometry data from cells overexpressing PKCD463H identify altered phosphorylation of substrates and binding to multiple proteins involved in cell-cell junctions compared to WT enzyme. Lastly, single nuclei RNAseq reveals that ChG derives from specialized tanycytes. Our data suggest that this disease-defining, fully penetrant mutation promotes neomorphic non-catalytic scaffolding to impair cell junction function.

Matching journals

The top 4 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.