Search bioRxiv⌕ Search

Biology subjects

Muraleedharan, R.

Publications and source records attributed to Muraleedharan, R..

2 recordsLinked to original sources

A cargo receptor entrapment complex is a therapeutic node for genetically and clinically distinct proteinopathies

Severe proteinopathies--such as retinitis pigmentosa, a form of inherited blindness--are driven by genetic mutations that overwhelm the quality control of the post-endoplasmic reticulum (post-ER) secretory pathway, causing toxic protein accumulation. Here, we identify a therapeutic node defined by a hetero-oligomeric cargo receptor complex consisting of TMED7, 2, 9, and 10. This "entrapment complex" anchors structurally and functionally diverse mutant clients within the early secretory pathway via TMED7 binding to the integral Golgi protein GRASP55. Disruption of the entrapment complex results in the clearance of accumulated protein cargoes. In vivo ablation of the entrapment node via inducible genetic deletion or via the small molecule BRD7635 reverses histopathological hallmarks and rescues functional deficits in clinically distinct proteinopathies of the kidney and the eye, including mitigating vision loss in a mouse model of retinitis pigmentosa.

cell biology↗

Integrative Multi-Omics Analysis Identifies Nuclear Factor I as a Key Driver of Dysregulated Purine Metabolism in DIPG

Diffuse intrinsic pontine glioma (DIPG) is a devastating brainstem cancer in children, with a median survival of under one year and limited treatment options. Over 80% of DIPGs possess a H3K27M mutation. To identify metabolic vulnerabilities linked to this mutation, we utilized a multi-omics approach in H3K27M-expressing cells, patient-derived cell lines, and mouse models. We show that by reprogramming chromatin landscape the mutation aberrantly induces NFI transcriptional activity, leading to misregulated purine metabolism. The mutation amplifies purine biosynthesis and degradation via the enzymes ATIC and PNP, respectively. Unregulated purine degradation relieves the negative feedback of purines on their own synthesis allowing continuous synthesis, use and degradation making DIPGs reliant on purine biosynthesis. Targeting ATIC reduced tumor progression and improved survival in mice. We propose ATIC as a potential novel target in DIPG.

cancer biology↗