Search bioRxiv⌕ Search

Biology subjects

Fonseca, D.

Publications and source records attributed to Fonseca, D..

2 recordsLinked to original sources

Dysregulation of synaptic-related genes within neuroimmune networks of peripheral blood mononuclear cells in major depressive disorder

Major depressive disorder (MDD) involves complex neuroimmune interactions linked to gene modulation. Our study investigates synaptic-related gene dysregulation in peripheral blood mononuclear cells (PBMCs) from MDD patients, showing how these immune cells mirror neural processes. Using RNA-seq data, we identified 1,383 differentially expressed genes (DEGs) related to neuroimmune crosstalk, with 49 DEGs effectively distinguishing MDD patients from controls based on synaptic functions. Synaptic genes, enriched for roles like vesicle transport, suggest mechanistic links between immune cells and neural signaling. Eleven synaptic-related DEGs were shared between PBMCs and brain regions involved in mood regulation, highlighting a common molecular signature. Among them, ADORA3 and RPS28 emerged as potential biomarkers. These findings highlight the potential of PBMCs in the diagnosis and treatment of MDD, reinforcing the development of future neuroimmune-targeted therapies for depression.

bioinformatics↗

The derlin Dfm1 promotes retrotranslocation of folded protein domains from the endoplasmic reticulum

Endoplasmic reticulum (ER) proteins are degraded by proteasomes in the cytosol through ER-associated degradation (ERAD). This process involves retrotranslocation of substrates across the ER membrane, their ubiquitination and subsequent membrane extraction by the Cdc48/Npl4/Ufd1 ATPase complex prior delivery to proteasomes for degradation. Recently a mechanism for the retrotranslocation of misfolded substrates by the Hrd1 ubiquitin ligase complex was described. However, how substrates with folded luminal domains are retrotranslocated remains unknown. Here, we identify Dfm1 as an essential membrane component for the retrotranslocation of proteins with folded luminal domains. Both Dfm1 intramembrane rhomboid-like and the cytosolic Cdc48-binding domains are essential for substrate retrotranslocation. Substrate processing by Dfm1 and Cdc48 complex requires the ubiquitin shuttle factors Rad23/Dsk2 and the multi-ubiquitination enzyme Ufd2. Our findings suggest a pathway in which a series of ubiquitin modifying factors recruit Dfm1 to resolve a stalled retrotranslocation intermediate due to the presence of a folded luminal domain.

cell biology↗