RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons

Developmental and epileptic encephalopathy (DEE) is a group of rare and serious neurological disorders where seizures exacerbate developmental impairment. Recently, genetic mutations in the RNF13 gene were reported to cause DEE73. Specifically, two leucines from the ubiquitin E3 ligase RNF13 are con...

Full description

Saved in:
Bibliographic Details
Main Authors: Valérie C. Cabana, Marc P. Lussier
Format: Article
Language:English
Published: Elsevier 2025-06-01
Series:IBRO Neuroscience Reports
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2667242125000521
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850222561505312768
author Valérie C. Cabana
Marc P. Lussier
author_facet Valérie C. Cabana
Marc P. Lussier
author_sort Valérie C. Cabana
collection DOAJ
description Developmental and epileptic encephalopathy (DEE) is a group of rare and serious neurological disorders where seizures exacerbate developmental impairment. Recently, genetic mutations in the RNF13 gene were reported to cause DEE73. Specifically, two leucines from the ubiquitin E3 ligase RNF13 are converted to serine or proline (L311S and L312P). These mutations are located within a dileucine motif, which impairs RNF13's capacity to interact with AP-3. A second motif allows RNF13 to interact with AP-1 when the dileucine sorting motif is altered. The present study demonstrates that RNF13 variants L311S and L312P are trafficked through an AP-1-dependent pathway in HeLa cells. In cultures of primary rat hippocampal neurons, the protein level of the variants is significantly higher in dendrites than for wild-type protein. L311S and L312P variants alter dendritic components similarly to an RNF13 AP-3-defective binding variant or a dominant negative for RNF13’s ubiquitin ligase activity. Compared to non-transfected neurons, the variants change the distribution of EEA1-positive early endosomes throughout the dendrites. While the WT alters the distribution of lysosomes (Lamp1-positive) in dendrites, the variants only decrease their presence in proximal dendrites. Unlike the variants, RNF13 WT increases the abundance of PSD-95 in distal dendrites. Interestingly, only the variants with altered dileucine motifs decrease the total number of postsynaptic inhibitory protein Gephyrin puncta. This study reports that genetic variants L311S and L312P mainly act as a dominant negative protein. This research provides valuable insights into the dendritic defects that occur when DEE73-associated genetic variants of RNF13 are present.
format Article
id doaj-art-7019e7ed7c9f426b96bd79faf1c3e586
institution OA Journals
issn 2667-2421
language English
publishDate 2025-06-01
publisher Elsevier
record_format Article
series IBRO Neuroscience Reports
spelling doaj-art-7019e7ed7c9f426b96bd79faf1c3e5862025-08-20T02:06:19ZengElsevierIBRO Neuroscience Reports2667-24212025-06-011855957310.1016/j.ibneur.2025.04.004RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neuronsValérie C. Cabana0Marc P. Lussier1Department of Chemistry, Université du Québec à Montréal, 2101, rue Jeanne-Mance, Montréal, QC H2X 2J6, Canada; CERMO-FC - The Center of Excellence in Research on Ophan Diseases - Fondation Courtois, Université du Québec à Montréal, Montréal, QC H2X 3Y7, Canada; PROTEO - The Quebec Network for Research on Protein Function, Engineering and Applications, Montréal, QC H3C 3P8, CanadaDepartment of Chemistry, Université du Québec à Montréal, 2101, rue Jeanne-Mance, Montréal, QC H2X 2J6, Canada; CERMO-FC - The Center of Excellence in Research on Ophan Diseases - Fondation Courtois, Université du Québec à Montréal, Montréal, QC H2X 3Y7, Canada; PROTEO - The Quebec Network for Research on Protein Function, Engineering and Applications, Montréal, QC H3C 3P8, Canada; Correspondence to: Département de Chimie, Université du Québec à Montréal, Faculté des Sciences, Succ. Centre-ville, Case postale 8888, Montreal, Québec H3C 3P8, Canada.Developmental and epileptic encephalopathy (DEE) is a group of rare and serious neurological disorders where seizures exacerbate developmental impairment. Recently, genetic mutations in the RNF13 gene were reported to cause DEE73. Specifically, two leucines from the ubiquitin E3 ligase RNF13 are converted to serine or proline (L311S and L312P). These mutations are located within a dileucine motif, which impairs RNF13's capacity to interact with AP-3. A second motif allows RNF13 to interact with AP-1 when the dileucine sorting motif is altered. The present study demonstrates that RNF13 variants L311S and L312P are trafficked through an AP-1-dependent pathway in HeLa cells. In cultures of primary rat hippocampal neurons, the protein level of the variants is significantly higher in dendrites than for wild-type protein. L311S and L312P variants alter dendritic components similarly to an RNF13 AP-3-defective binding variant or a dominant negative for RNF13’s ubiquitin ligase activity. Compared to non-transfected neurons, the variants change the distribution of EEA1-positive early endosomes throughout the dendrites. While the WT alters the distribution of lysosomes (Lamp1-positive) in dendrites, the variants only decrease their presence in proximal dendrites. Unlike the variants, RNF13 WT increases the abundance of PSD-95 in distal dendrites. Interestingly, only the variants with altered dileucine motifs decrease the total number of postsynaptic inhibitory protein Gephyrin puncta. This study reports that genetic variants L311S and L312P mainly act as a dominant negative protein. This research provides valuable insights into the dendritic defects that occur when DEE73-associated genetic variants of RNF13 are present.http://www.sciencedirect.com/science/article/pii/S2667242125000521RNF13Developmental and epileptic encephalopathyE3 ubiquitin ligaseEndolysosomal systemDendrites
spellingShingle Valérie C. Cabana
Marc P. Lussier
RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons
IBRO Neuroscience Reports
RNF13
Developmental and epileptic encephalopathy
E3 ubiquitin ligase
Endolysosomal system
Dendrites
title RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons
title_full RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons
title_fullStr RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons
title_full_unstemmed RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons
title_short RNF13 variants L311S and L312P associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons
title_sort rnf13 variants l311s and l312p associated with developmental epileptic encephalopathy alter dendritic organization in hippocampal neurons
topic RNF13
Developmental and epileptic encephalopathy
E3 ubiquitin ligase
Endolysosomal system
Dendrites
url http://www.sciencedirect.com/science/article/pii/S2667242125000521
work_keys_str_mv AT valerieccabana rnf13variantsl311sandl312passociatedwithdevelopmentalepilepticencephalopathyalterdendriticorganizationinhippocampalneurons
AT marcplussier rnf13variantsl311sandl312passociatedwithdevelopmentalepilepticencephalopathyalterdendriticorganizationinhippocampalneurons