COVID-19 researchGene: DAG1
Evidence Summary from Illumina curation team (Alison Coffey and Julie Taylor): The DAG1 gene encodes 2 dystroglycan proteins, both of which are dystrophin-associated glycoproteins (DAGs) (OMIM:128239). Alpha-Dystroglycan (a-DG) is a common receptor for lymphocytic choriomeningitis virus (LCMV) and several other arenaviruses including the human pathogenic Lassa fever virus (Imperiali et al. 2005; Kunz et al. 2009; Rojek et al. 2007).
PubMed 16254364: Imperiali et al. (2005) - alpha-Dystroglycan (a-DG) was identified as a common receptor for lymphocytic choriomeningitis virus (LCMV) and several other arenaviruses including the human pathogenic Lassa fever virus. Arenaviruses are enveloped, single-stranded RNA viruses with a bisegmented ambisense genome. Susceptibility toward LCMV infection differed in various cell lines despite them expressing comparable levels of DG, suggesting that posttranslational modifications of a-DG would be involved in viral receptor function. Demonstrated that glycosylation of a-DG, and in particular, O mannosylation, which is a rare type of O-linked glycosylation in mammals, is essential for LCMV receptor function. Cells that are defective in components of the O-mannosylation pathway showed strikingly reduced LCMV infectibility. As defective O mannosylation is associated with severe clinical symptoms in mammals such as congenital muscular dystrophies, it is likely that LCMV and potentially other arenaviruses may have selected this conserved and crucial posttranslational modification as the primary target structure for cell entry and infection.
PMID 19324387: Kunz et al. (2009) - Old World arenaviruses LCMV (lymphocytic choriomeningitis virus) and LASV (Lassa virus) enter the host cell predominantly via a novel and unusual endocytotic pathway independent of clathrin, caveolin, dynamin, and actin. Infection of cells with LCMV and LASV depends on DG, this unusual endocytotic pathway could be related to normal cellular trafficking of the DG complex. Arenavirus particles may target DG for an endocytotic pathway not normally used in uninfected cells thereby inducing an entry route specifically tailored to the pathogen's needs.
PMID 17360738: Rojek et al. (2007) - Found that protein O mannosylation of α-DG is crucial for the binding of arenaviruses of distinct phylogenetic origins, including LFV, Mobala virus, and clade C New World arenaviruses.
Observed that overexpression of LARGE in cells deficient in O mannosylation resulted in highly glycosylated α-DG that was functional as a receptor for arenaviruses. Demonstrate that arenaviruses recognize the same highly conserved O-glycan structures on α-DG involved in ECM protein binding, indicating a strikingly similar mechanism of receptor recognition by pathogen- and host-derived ligands.
PMID 21185048: Oldstone et al. (2011) - Dendritic cells (DC)s express the highest levels of α-DG and are the sentinel cells that LCMV, and presumably also LFV, infect. The resultant infection of DCs compromises DC function.
Determinant of injury is the displacement of laminin or other ECM molecules that bind to the same site on α-DG that LCMV and LFV seek. When ECM molecules are pushed aside, the virus destabilizes membranes and causes interference with ECM signals that are required to maintain homeostasis.
PMID 15857984: Kunz et al. (2005) show that LFV (Lassa fever virus) binds to α-DG with high affinity in the low-nanomolar range. Recombinant vesicular stomatitis virus pseudotyped with LFV glycoprotein (GP) adopted the receptor binding characteristics of LFV and depended on α-DG for infection of cells.
LFV was found to efficiently compete with laminin α1 and α2 chains for α-DG binding.
LCMV uses the same domains of α-DG for binding that are used in LFV binding.
Findings indicate a high degree of conservation in the receptor binding characteristics between the highly human-pathogenic LFV and murine-immunosuppressive LCMV isolates.
Created: 28 May 2020, 3:30 p.m. | Last Modified: 2 Jun 2020, 8:20 p.m.
Panel Version: 1.1
Identified through an OMIM search for potential viral susceptibility genes, and subsequently triaged/reviewed by Illumina curation team.
Created: 28 May 2020, 12:36 p.m. | Last Modified: 28 May 2020, 12:36 p.m.
Panel Version: 0.336
gene: DAG1 was added gene: DAG1 was added to COVID-19 research. Sources: Expert list,OMIM,Expert Review Green Mode of inheritance for gene: DAG1 was set to Unknown