scholarly journals A Sialic Acid-Binding Protein SABP1 of Toxoplasma gondii Mediates Host Cell Attachment and Invasion

2020 ◽  
Vol 222 (1) ◽  
pp. 126-135 ◽  
Author(s):  
Mengen Xing ◽  
Na Yang ◽  
Ning Jiang ◽  
Dawei Wang ◽  
Xiaoyu Sang ◽  
...  

Abstract Many obligate intracellular apicomplexan parasites have adapted a distinct invasion mechanism involving a close interaction between the parasite ligands and the sialic acid (SA) receptor. We found that sialic acid binding protein-1 (SABP1), localized on the outer membrane of the zoonotic parasite Toxoplasma gondii, readily binds to sialic acid on the host cell surface. The binding was sensitive to neuraminidase treatment. Cells preincubated with recombinant SABP1 protein resisted parasite invasion in vitro. The parasite lost its invasion capacity and animal infectivity after the SABP1 gene was deleted, whereas complementation of the SABP1 gene restored the virulence of the knockout strain. These data establish the critical role of SABP1 in the invasion process of T. gondii. The previously uncharacterized protein, SABP1, facilitated T. gondii attachment and invasion via sialic acid receptors.

2004 ◽  
Vol 78 (15) ◽  
pp. 8094-8101 ◽  
Author(s):  
Peter L. Delputte ◽  
Hans J. Nauwynck

ABSTRACT Recently, we showed that porcine sialoadhesin (pSn) mediates internalization of the arterivirus porcine reproductive and respiratory syndrome virus (PRRSV) in alveolar macrophages (Vanderheijden et al., J. Virol. 77:8207-8215, 2003). In rodents and humans, sialoadhesin, or Siglec-1, has been described as a macrophage-restricted molecule and to specifically bind sialic acid moieties. In the current study, we investigated whether pSn is a sialic acid binding protein and, whether so, whether this property is important for its function as a PRRSV receptor. Using untreated and neuraminidase-treated sheep erythrocytes, we showed that pSn binds sialic acid. Furthermore, pSn-specific monoclonal antibody 41D3, which blocks PRRSV infection, inhibited this interaction. PRRSV attachment to and infection of porcine alveolar macrophages (PAM) were both shown to be dependent on the presence of sialic acid on the virus: neuraminidase treatment of virus but not of PAM blocked infection and reduced attachment. Enzymatic removal of all N-linked glycans on the virus with N-glycosidase F reduced PRRSV infection, while exclusive removal of nonsialylated N-linked glycans of the high-mannose type with endoglycosidase H had no significant effect. Free sialyllactose and sialic acid containing (neo)glycoproteins reduced infection, while lactose and (neo)glycoproteins devoid of sialic acids had no significant effect. Studies with linkage-specific neuraminidases and lectins indicated that α2-3- and α2-6-linked sialic acids on the virion are important for PRRSV infection of PAM. From these results, we conclude that pSn is a sialic acid binding lectin and that interactions between sialic acid on the PRRS virion and pSn are essential for PRRSV infection of PAM.


1993 ◽  
Vol 7 (9) ◽  
pp. 667-670 ◽  
Author(s):  
Larisa S. Zhigis ◽  
Alexander E. Ivanov ◽  
Eugenya M. Rapoport ◽  
Emma A. Kovalenko ◽  
Ekaterina I. Getman ◽  
...  

1989 ◽  
Vol 163 (1) ◽  
pp. 506-512 ◽  
Author(s):  
Hans-J. Gabius ◽  
Attila Bardosi ◽  
Sigrun Gabius ◽  
Klaus P. Hellmann ◽  
Michael Karas ◽  
...  

2019 ◽  
Author(s):  
Peter Thuy-Boun ◽  
Dennis Wolan

<p>To identify sialic acid binding proteins from complex proteomes, three photocrosslinking affinity-based probes were constructed using Neu5Ac (<b>5 </b>and <b>6</b>) and Neu5Ac2en (<b>7</b>) scaffolds. Kinetic inhibition assays and Western blotting revealed the Neu5Ac2en-based <b>7 </b>to be an effective probe for the labeling of a purified gut microbial sialidase (BDI_2946) and a purified human sialic acid binding protein (hCD33). Additionally, LC-MS/MS affinity-based protein profiling verified the ability of <b>7</b>to enrich a low-abundance sialic acid binding protein (complement factor H) from human serum thus validating the utility of this probe in a complex context.</p>


1986 ◽  
Vol 53 (2) ◽  
pp. 359-365 ◽  
Author(s):  
P A Murray ◽  
M J Levine ◽  
M S Reddy ◽  
L A Tabak ◽  
E J Bergey

2019 ◽  
Vol 10 (24) ◽  
pp. 6199-6209 ◽  
Author(s):  
Qiongyu Li ◽  
Yixuan Xie ◽  
Gege Xu ◽  
Carlito B. Lebrilla

A “protein oxidation of sialic acid environments” (POSE) mapping tool is developed for sialic acid binding protein discovery.


2019 ◽  
Author(s):  
Peter Thuy-Boun ◽  
Dennis Wolan

<p>To identify sialic acid binding proteins from complex proteomes, three photocrosslinking affinity-based probes were constructed using Neu5Ac (<b>5 </b>and <b>6</b>) and Neu5Ac2en (<b>7</b>) scaffolds. Kinetic inhibition assays and Western blotting revealed the Neu5Ac2en-based <b>7 </b>to be an effective probe for the labeling of a purified gut microbial sialidase (BDI_2946) and a purified human sialic acid binding protein (hCD33). Additionally, LC-MS/MS affinity-based protein profiling verified the ability of <b>7</b>to enrich a low-abundance sialic acid binding protein (complement factor H) from human serum thus validating the utility of this probe in a complex context.</p>


PLoS ONE ◽  
2015 ◽  
Vol 10 (11) ◽  
pp. e0143898 ◽  
Author(s):  
Peng Zhou ◽  
Jinman Liu ◽  
Xiaoli Li ◽  
Yukihiro Takahashi ◽  
Fengxia Qi

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