Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.B1 (angiotensin-converting enzyme 2)
 1,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Severe acute respiratory syndrome (SARS) is caused by a newly emerged coronavirus (CoV) designated SARS-CoV. The virus utilizes angiotensin-converting enzyme 2 (ACE2) as the primary receptor. Although the idea is less clear and somewhat controversial, SARS-CoV is thought to use C-type lectins DC-SIGN and/or L-SIGN (collectively referred to as DC/L-SIGN) as alternative receptors or as enhancer factors that facilitate ACE2-mediated virus infection. In this study, the function of DC/L-SIGN in SARS-CoV infection was examined in detail. The results of our study clearly demonstrate that both proteins serve as receptors independently of ACE2 and that there is a minimal level of synergy between DC/L-SIGN and ACE2. As expected, glycans on spike (S) glycoprotein are important for DC/L-SIGN-mediated virus infection. Site-directed mutagenesis analyses have identified seven glycosylation sites on the S protein critical for DC/L-SIGN-mediated virus entry. They include asparagine residues at amino acid positions 109, 118, 119, 158, 227, 589, and 699, which are distinct from residues of the ACE2-binding domain (amino acids 318 to 510). Amino acid sequence analyses of S proteins encoded by viruses isolated from animals and humans suggest that glycosylation sites N227 and N699 have facilitated zoonotic transmission.
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PMID:Specific asparagine-linked glycosylation sites are critical for DC-SIGN- and L-SIGN-mediated severe acute respiratory syndrome coronavirus entry. 1771 38

Identification of the nature of severe acute respiratory syndrome (SARS)-infected cells is crucial toward understanding the pathogenesis. Using multicolor colocalization techniques, we previously reported that SARS(+) cells in the lung of fatally infected patients expressed the only known functional receptor, angiotensin-converting enzyme 2, and also a binding receptor, liver/lymph node-specific ICAM-3-grabbing non-integrin (CD209L). In this study, we show that SARS-infected cells also express the stem/progenitor cell markers CD34 and Oct-4, and do not express cytokeratin or surfactant. These putative lung stem/progenitor cells can also be identified in some non-SARS individuals and can be infected by SARS-coronavirus ex vivo. Infection of these cells may contribute to the loss of lung repair capacity that leads to respiratory failure as clinically observed.
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PMID:A novel subset of putative stem/progenitor CD34+Oct-4+ cells is the major target for SARS coronavirus in human lung. 1792 1

The spike protein (S) of SARS-CoV-2 mediates entry into human cells by interacting with human angiotensin-converting enzyme 2 (ACE2) through its receptor-binding domain (RBD). Here, we report identification of CD209L/L-SIGN and a related protein, CD209/DSIGN as alternative receptors capable of mediating SARS-CoV-2 entry into human cells. Immunofluorescence staining of human tissues revealed a prominent expression of CD209L in the lung and kidney epithelial and endothelial cells of small and medium-sized vessels, whereas CD209 was detected only in a limited number of cell types. Biochemical assays revealed that ectopically expressed CD209L and CD209 bind to S-RBD and mediate SARS-CoV-2 S-pseudotyped virus entry. Furthermore, we demonstrate that human endothelial cells endogenously express CD209L and are permissive to SARS-CoV-2 infection. Soluble CD209L-Fc neutralized virus entry. Our observations show that CD209L and CD209 serve as alternative receptors for SARS-CoV-2 in disease-relevant cell types, including the vascular system. This may have implications for antiviral drug development.
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PMID:CD209L/L-SIGN and CD209/DC-SIGN act as receptors for SARS-CoV-2 and are differentially expressed in lung and kidney epithelial and endothelial cells. 3260 6