Browsing by Author "Suliman, Tasnim"

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    Comparative analysis of human coronavirus-NL63 ORF3 protein homologues
    (Academic Journals, 2009) Fielding, Burtram C.; Suliman, Tasnim
    It has been reported in some studies that the newly discovered human coronavirus NL-63 (HCoVNL63) is one of the most common coronaviruses associated with acute respiratory infections. HCoVNL63 was first isolated in 2004 from a 7 month old infant in Holland. The HCoV-NL63 genome encodes for one accessory protein, ORF3. This reports the computational analysis of human coronavirus NL63 ORF3 by comparing the amino acid sequences of coronavirus ORF3-homologues. The HCoV-NL63 ORF3 gene was found to encode a putative protein ~25.6 kDa in size. ORF3 was predicted to contain three potential transmembrane regions. The amino acid sequence of HCoVNL63 ORF3 was shown to be most similar to HCoV 229E ORF4 (43% identity; 62% similarity).
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    Distinct phenotype of SARS-CoV-2 Omicron BA.1 in human primary cells but no increased host range in cell lines of putative mammalian reservoir species
    (Elsevier B.V., 2024) Essaidi-Laziosi, Manel; Suliman, Tasnim; Pérez-Rodríguez, Francisco J.
    SARS-CoV-2′s genetic plasticity has led to several variants of concern (VOCs). Here we studied replicative capacity for seven SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta, and Omicron BA.1) in primary reconstituted airway epithelia (HAE) and lung-derived cell lines. Furthermore, to investigate the host range of Delta and Omicron compared to ancestral SARS-CoV-2, we assessed replication in 17 cell lines from 11 non-primate mammalian species, including bats, rodents, insectivores and carnivores. Only Omicron's phenotype differed in vitro, with rapid but short replication and efficient production of infectious virus in nasal HAEs, in contrast to other VOCs, but not in lung cell lines. No increased infection efficiency for other species was observed, but Delta and Omicron infection efficiency was increased in A549 cells. Notably replication in A549 and Calu3 cells was lower than in nasal HAE. Our results suggest better adaptation of VOCs towards humans, without an extended host range, and may be relevant to the search for the putative intermediate host and reservoirs prior to the pandemic.
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    Human coronavirus NL63 open reading frame 3 encodes a virion-incorporated N-glycosylated membrane protein
    (BioMed Central, 2010) Müller, Marcel A.; van der Hoek, Lia; Voss, Daniel; Bader, Oliver; Lehmann, Dörte; Schulz, Axel R.; Kallies, Stephan; Suliman, Tasnim; Fielding, Burtram C.; Drosten, Christian; Niedrig, Matthias
    Background: Human pathogenic coronavirus NL63 (hCoV-NL63) is a group 1 (alpha) coronavirus commonly associated with respiratory tract infections. In addition to known non-structural and structural proteins all coronaviruses have one or more accessory proteins whose functions are mostly unknown. Our study focuses on hCoV-NL63 open reading frame 3 (ORF 3) which is a highly conserved accessory protein among coronaviruses. Results: In-silico analysis of the 225 amino acid sequence of hCoV-NL63 ORF 3 predicted a triple membranespanning protein. Expression in infected CaCo-2 and LLC-MK2 cells was confirmed by immunofluorescence and Western blot analysis. The protein was detected within the endoplasmatic reticulum/Golgi intermediate compartment (ERGIC) where coronavirus assembly and budding takes place. Subcellular localization studies using recombinant ORF 3 protein transfected in Huh-7 cells revealed occurrence in ERGIC, Golgi- and lysosomal compartments. By fluorescence microscopy of differently tagged envelope (E), membrane (M) and nucleocapsid (N) proteins it was shown that ORF 3 protein colocalizes extensively with E and M within the ERGIC. Using N-terminally FLAG-tagged ORF 3 protein and an antiserum specific to the C-terminus we verified the proposed topology of an extracellular N-terminus and a cytosolic C-terminus. By in-vitro translation analysis and subsequent endoglycosidase H digestion we showed that ORF 3 protein is N-glycosylated at the N-terminus. Analysis of purified viral particles revealed that ORF 3 protein is incorporated into virions and is therefore an additional structural protein. Conclusions: This study is the first extensive expression analysis of a group 1 hCoV-ORF 3 protein. We give evidence that ORF 3 protein is a structural N-glycosylated and virion-incorporated protein.