Dataset Information

Development and initial characterization of cellular models for COG complexrelated CDG-II diseases

ABSTRACT: Conserved Oligomeric Golgi (COG) is an octameric protein complex that orchestrates intra-Golgi trafficking of glycosylation enzymes. Over a hundred individuals with 31 different COG mutations have been identified until now. The cellular phenotypes and clinical presentations of COG-CDGs are heterogeneous, and patients primarily represent neurological, skeletal, and hepatic abnormalities. The establishment of a cellular COG disease model will benefit the molecular study of the disease, explaining the detailed sequence of the interplay between the COG complex and the trafficking machinery. Moreover, patient fibroblasts are not a good representative of all the organ systems and cell types that are affected by COG mutations. We developed and characterized cellular models for human COG4 mutations specifically in RPE1 and HEK293T cell lines. Using a combination of CRISPR/Cas9 and lentiviral transduction technologies, both myc-tagged wild-type and mutant (G516R and R729W) COG4 proteins were expressed under the endogenous COG4 promoter. Constructed isogenic cell lines were comprehensively characterized using biochemical, microscopy (superresolution and electron), and proteomics approaches. The analysis revealed similar stability and localization of COG complex subunits, wild-type cell growth, and normal Golgi morphology in all three cell lines. Importantly, COG4-G516R cells demonstrated increased HPA-647 binding to the plasma membrane glycoconjugates, while COG4-R729W cells revealed high GNL-647 binding, indicating specific defects in O- and N-glycosylation. Both mutant cell lines express elevated level of heparin sulfate proteoglycans. Moreover, a quantitative mass-spectrometry analysis of proteins secreted by COG-deficient cell lines revealed abnormal secretion of SIL1 and ERGIC-53 proteins by COG4-G516R cells. Interestingly, the clinical phenotype of patients with congenital mutations in SIL1 gene (Marinesco-Sjogren syndrome) overlaps with the phenotype of COG4-G516R patients (Saul-Wilson syndrome). Our work is the first compressive study involving the creation of different COG mutations in different cell lines other than patient’s fibroblast. It may help to address the underlying cause of the phenotypic defects leading to the discovery of a proper treatment guideline for COG-CDGs.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Stephanie Byrum

LAB HEAD: Vladimir Lupashin

PROVIDER: PXD027202 | Pride | 2022-02-17

REPOSITORIES: Pride

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Publications

Development and Initial Characterization of Cellular Models for COG Complex-Related CDG-II Diseases.

Sumya Farhana Taher FT Pokrovskaya Irina D ID Lupashin Vladimir V

Frontiers in genetics 20210917

Conserved Oligomeric Golgi (COG) is an octameric protein complex that orchestrates intra-Golgi trafficking of glycosylation enzymes. Over a hundred individuals with 31 different COG mutations have been identified until now. The cellular phenotypes and clinical presentations of COG-CDGs are heterogeneous, and patients primarily represent neurological, skeletal, and hepatic abnormalities. The establishment of a cellular COG disease model will benefit the molecular study of the disease, explaining ...[more]

PMID: 34603392

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Project description:Functional decline and structural alterations of the brain microvasculature are associated with cognitive impairment and development of dementias such as Alzheimer’s disease during aging. Although mechanisms of leading to microvascular changes during aging are not clear, the loss of mitochondria and reduced efficiency of remaining mitochondria appear to play a major role. While pharmacological agents which target mitochondria such as SS-31 have been shown to be effective in beneficial during aging and diseases, the full extent on mitochondrial- and non-mitochondrial proteins in the brain microvasculature has not been examined. We tested the hypothesis that attenuation of aging-associated changes in the brain microvascular proteome via targeting mitochondria represents a therapeutic option in the aging brain. We used male, aged (>18 months) C57Bl6/J mice treated with a mitochondria-targeted tetrapeptide, SS-31 or vehicle saline. Baseline cerebral blood flow (CBF) was determined using laser speckle imaging during the two-week treatment period. Then, isolated cortical microvessels (MVs), composed of end arterioles, capillaries, and venules, were used for Orbitrap Eclipse Tribrid mass spectrometry. Baseline CBF was similar between the groups, whereas bioinformatic analysis revealed substantial differences in protein abundance of cortical MVs between SS-31 and vehicle groups. Specifically, we identified 6,266 proteins in our data set from which 12% were mitochondrial or mitochondria associated. 107 of these proteins were significantly differentially expressed between the treatment and vehicle groups, and were associated with the oxidative phosphorylation, metabolism, antioxidant defense system, or mitochondrial dynamics. Administration of SS-31 also affected many non-mitochondrial proteins. Our findings suggest that mitochondria in the microvasculature represent a therapeutic target in the aging brain, and widespread changes in the proteome may underlie the mechanisms of rejuvenating actions of SS-31 in the aging phenotype.

Dataset Information

Development and initial characterization of cellular models for COG complexrelated CDG-II diseases

Publications

Development and Initial Characterization of Cellular Models for COG Complex-Related CDG-II Diseases.

Similar Datasets

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