Gerardo R Vasta

Gerardo R Vasta
University of Maryland, Baltimore | UMB · Department of Microbiology and Immunology

Ph.D.

About

251
Publications
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Publications

Publications (251)
Article
Techniques for disrupting gene expression are invaluable tools for the analysis of the biological role of a gene product. Because of its genetic tractability and multiple advantages over conventional mammalian models, the zebrafish (Danio rerio) is recognized as a powerful system for gaining new insight into diverse aspects of human health and dise...
Chapter
Protein–carbohydrate interactions are essential to both intra- and extracellular physiological processes, including glycoprotein folding, sorting, and secretion, cell adhesion, cell-cell communication and signaling, and immune functions. Lectins, are carbohydrate-binding proteins or glycoproteins that participate in the aforementioned processes by...
Article
In this issue of Structure, Gadjos et al. (2021b) determine the structure of a bacterial lectin in complex with L-fucose by neutron diffraction of both perdeuterated protein and carbohydrate ligand. The structure provides insight into lectin-ligand interactions, opening avenues for drug design targeting bacterial lectins for intervention in infecti...
Chapter
Carbohydrate-binding proteins known as “lectins” comprise a wide variety of molecular species, widely distributed in viruses, prokaryotes, and eukaryotes, including plants and animals.1, 2, 3 While lectins are structurally diverse, they all share in common the presence of one or more carbohydrate recognition domains (CRDs) that can also be associat...
Article
The increasing availability of sequenced genomes has enabled a deeper understanding of the complexity of fish lectin repertoires involved in early development and immune recognition. The teleost fucose-type lectin (FTL) family includes proteins that preferentially bind fucose and display tandemly arrayed carbohydrate-recognition domains (CRDs) or a...
Chapter
The purification of fucose-binding lectins from the liver of striped bass (Morone saxatilis), a teleost fish, and the identification of a novel lectin sequence motif led to the identification of a new family of lectins, the F-type lectins (FTLs) (see overview of the FTL family in Chapter 23). Isolation and purification of these proteins from liver...
Chapter
F-type lectins (FTLs) are characterized by a fucose recognition domain (F-type lectin domain; FTLD) that displays a novel jellyroll fold (“F-type” fold) and unique carbohydrate- and calcium-binding sequence motifs. This novel lectin family comprises widely distributed proteins exhibiting single, double, or greater multiples of the FTLD, either tand...
Article
Pregnancy-specific beta 1 glycoprotein (PSG1) is secreted from trophoblast cells of the human placenta in increasing concentrations as pregnancy progresses, becoming one of the most abundant proteins in maternal serum in the third trimester. PSG1 has seven potential N-linked glycosylation sites across its four domains. We carried out glycomic and g...
Article
C-type lectins (CTLs) are key recognition proteins in shrimp immunity. A few years ago we reviewed sequence information, ligand specificity, expression profiles and specific functions of the shrimp CTLs. Since then, multiple integrated studies that implemented biochemical approaches using both the native and recombinant proteins, functional genetic...
Article
Galectins are a structurally conserved family of ß-galactoside-binding lectins characterized by a unique sequence motif in the carbohydrate recognition domain, and of wide taxonomic distribution, from fungi to mammals. Their biological functions, initially described as key to embryogenesis and early development via recognition of endogenous (“self”...
Chapter
Galectins are a family of ß-galactoside-binding lectins characterized by a unique sequence motif in the carbohydrate recognition domain, and evolutionary and structural conservation from fungi to invertebrates and vertebrates, including mammals. Their biological roles, initially understood as limited to recognition of endogenous (“self”) carbohydra...
Article
Full-text available
Both vertebrates and invertebrates display active innate immune mechanisms for defense against microbial infection, including diversified repertoires of soluble and cell-associated lectins that can effect recognition and binding to potential pathogens, and trigger downstream effector pathways that clear them from the host internal milieu. Galectins...
Article
Full-text available
Background: Antioxidative enzymes contribute to a parasite's ability to counteract the host's intracellular killing mechanisms. The facultative intracellular oyster parasite, Perkinsus marinus, a sister taxon to dinoflagellates and apicomplexans, is responsible for mortalities of oysters along the Atlantic coast of North America. Parasite trophozo...
Article
Full-text available
Galectins are a phylogenetically conserved family of soluble β-galactoside binding proteins, consisting of 15 different types, each with a specific function. Galectins contribute to placentation by regulating trophoblast development, migration, and invasion during early pregnancy. In addition, galectins are critical players regulating maternal immu...
Article
Galectins, highly conserved β-galactoside-binding lectins, have diverse regulatory roles in development and immune homeostasis and can mediate protective functions during microbial infection. In recent years, the role of galectins in viral infection has generated considerable interest. Studies on highly pathogenic viruses have provided invaluable i...
Chapter
The study of molluscan immune systems, in particular those of bivalve molluscs (e.g., clams, oysters, scallops, mussels), has experienced great growth in recent decades, mainly due to the needs of a rapidly growing aquaculture industry to manage the impacts of disease and the wider application of -omic tools to this diverse group of invertebrate or...
Article
Full-text available
Antimicrobial peptides (AMPS) are ancestral components in the evolution of immunity from protozoans to metazoans. Their expression can be constitutive or inducible by infectious challenge. Although characterized in detail in their structure and activity, the temporal and spatial expression of AMPS during vertebrate embryogenesis is still poorly und...
Article
Full-text available
The F-type lectin (FTL) family is one of the most recent to be identified and structurally characterized. Members of the FTL family are characterized by a fucose recognition domain [F-type lectin domain (FTLD)] that displays a novel jellyroll fold (“F-type” fold) and unique carbohydrate- and calcium-binding sequence motifs. This novel lectin family...
Article
Full-text available
C-type lectins (CTLs) are characterized by the presence of a C-type carbohydrate recognition domain (CTLD) that by recognizing microbial glycans, is responsible for their roles as pattern recognition receptors in the immune response to bacterial infection. In addition to the CTLD, however, some CTLs display additional domains that can carry out eff...
Data
The Dome, JAK and STAT domain architectures, and tissue distribution and expression patterns of Dome and JAK in shrimp. (A) JAK from M. japonicus contains a B41 (Band 4.1 homologues), a SH2 (Src homology 2 domain) and two protein kinase activity domains. STAT from M. japonicus contains a NTD (N-terminal domain), a CC (coiled-coil domain), a DB (DNA...
Data
Bacteria maximum binding parameter (Bmax) and dissociation constant (Kd) of CC-CTL to different polysaccharides. Nonlinear regression analysis showed that the binding of rMjCC-CL, rMjCC and rMjCTL to different polysaccharides fitted a two-site binding model (R2 > 0.96). Bmax of MjCC-CTL binding to LPS from E. coli and PGN from S. aureus and PGN fro...
Data
Recombinant proteins of GST, GST-MjCC-CL, GST-IL domain, GST-CTL domain and His-Dome-ILR were expressed and purified from E. coli. (A) GST expression and purification. (B-E) GST-MjCC-CL (B). GST-CC domain of MjCC-CL (C). GST-CTL domain of MjCC-CL (D). His-Dome-ILR (E). Lane M, protein marker; lane 1, proteins of E. coli with recombinant vectors bef...
Data
Nucleotide sequence of CruI-1 promotor. Genome walking was used for obtaining genomic sequence of CruΙ-1. The binding sites of CruΙ-1 genomic sequence were marked. NF-κB (Rel) binding site marked with gray; NF-κB (RelA) binding site marked with blue; Stat1/2 binding site marked with green; Stat5a/5b binding site marked with red; a TATA box marked w...
Data
Sequences of the primers used in this study. (TIF)
Article
Carbohydrate structures on the cell surface encode complex information that through specific recognition by carbohydrate-binding proteins (lectins), modulates interactions between cells, cells and the extracellular matrix, or mediates recognition of potential microbial pathogens. Galectins are a family of ß-galactoside-binding lectins, which are ev...
Article
Full-text available
Zebrafish spontaneously regenerate the retina after injury. Although the gene expression profile has been extensively studied in this species during regeneration, this does not reflect protein function. To further understand the regenerative process in the zebrafish, we compared the proteomic profile of the retina during injury and upon regeneratio...
Chapter
Lectins are sugar-binding proteins widely distributed among animals, plants, and microbial taxon, involved in diverse biological processes. In both invertebrates and vertebrates, they play key roles in nonself recognition and immune responses, such as nonself recognition, inflammatory processes, and immunomodulation. In fish, many lectin families h...
Article
Full-text available
Perkinsus marinus is a protozoan parasite of molluscs that can be propagated in vitro in a defined culture medium, in the absence of host cells. We previously reported that P. marinus trophozoites can be transfected with high efficiency by electroporation using a plasmid based on MOE, a highly expressed gene, and proposed its potential use as a "ps...
Chapter
The key roles of soluble and cell-associated lectins as recognition/effector factors in immune responses of both invertebrates and vertebrates are now widely recognized. Unlike immunoglobulins, most lectins do not generate diversity in recognition by genetic recombination. However, the presence of multiple isoforms with distinct binding specificity...
Article
Full-text available
Influenza patients frequently display increased susceptibility to Streptococcus pneumoniae co-infectionand sepsis, the prevalent cause of mortality during influenza pandemics. However, the detailed mechanisms by which an influenza infection predisposes patients to suffer pneumococcal pneumonia are not fully understood. A murine model for influenza...
Article
Galectins are highly conserved lectins that are key to multiple biological functions, including pathogen recognition and regulation of immune responses. We previously reported that CvGal1, a galectin expressed in phagocytic cells (hemocytes) of the eastern oyster (Crassostrea virginica), is "hijacked" by the parasite Perkinsus marinus to enter the...
Article
Galectins constitute a conserved and widely distributed lectin family characterized by their binding affinity for ß-galactosides and a unique binding site sequence motif in the carbohydrate recognition domain (CRD). In spite of their structural conservation, galectins display a remarkable functional diversity, by participating in developmental proc...
Article
Full-text available
The continued threat of worldwide influenza pandemics, together with the yearly emergence of antigenically drifted influenza A virus (IAV) strains, underscore the urgent need to elucidate not only the mechanisms of influenza virulence, but also those mechanisms that predispose influenza patients to increased susceptibility to subsequent infection w...
Article
Full-text available
Techniques for disrupting gene expression are invaluable tools for the analysis of the biological role(s) of a gene product. Because of its genetic tractability and multiple advantages over conventional mammalian models, the zebrafish (Danio rerio) is recognized as a powerful system for gaining new insight into diverse aspects of human health and d...
Article
Full-text available
Bivalve molluscs are key components of the estuarine environments as contributors to the trophic chain, and as filter -feeders, for maintaining ecosystem integrity. Further, clams, oysters, and scallops are commercially exploited around the world both as traditional local shellfisheries, and as intensive or semi-intensive farming systems. During th...
Conference Paper
Helicobacter spp. cause prevalent infections worldwide in both humans and animals, and are recognized as the causative agents of chronic gastritis, gastric ulcers and, in some cases, gastric adenocarcinoma and MALT lymphoma. About half of the human population worldwide carries H. pylori, and although this species is perhaps one of the world’s most...
Article
Full-text available
Galectins are a lectin family characterized by a conserved sequence motif in the carbohydrate recognition domain, which preferential binds to galactosyl moieties. However, few studies about the biological roles of galectins in invertebrates have been reported except for the galectin (CvGal1) from the eastern oyster Crassostrea virginica. Furthermor...
Article
Full-text available
Some aquatic invertebrates such as shrimp contain low albeit stable numbers of bacteria in the circulating hemolymph. The proliferation of this hemolymph microbiota in such a nutrient-rich environment is tightly controlled in healthy animals, but the mechanisms responsible had remained elusive. In the present study, we report a C-type lectin (MjHeC...
Article
Full-text available
Perkinsus marinus (Phylum Perkinsozoa) is a marine protozoan parasite responsible for "Dermo" disease in oysters, which has caused extensive damage to the shellfish industry and estuarine environment. The infection prevalence has been estimated in some areas to be as high as 100%, often causing death of infected oysters within 1-2 years post-infect...
Article
Full-text available
Perkinsus marinus is a protozoan parasite that causes ‘‘Dermo’’ disease in the eastern oyster Crasssostrea virginica in coastal areas of the USA. Until now, intervention strategies against the parasite have found limited success, and Dermo still remains one of the main hurdles for the restoration of oyster populations. We adapted a commercial adeno...
Article
Full-text available
The galectin CvGal1 from the eastern oyster (Crassostrea virginica), which possesses four tandemly arrayed carbohydrate recognition domains, was previously shown to display stronger binding to galactosamine and N-acetylgalactosamine relative to d-galactose. CvGal1 expressed by phagocytic cells is “hijacked” by the parasite Perkinsus marinus to ente...
Article
Full-text available
The eastern oyster (Crassostrea virginica) has become a useful model system for glycan-dependent host-parasite interactions due to the hijacking of the oyster galectin CvGal1 for host entry by the protozoan parasite Perkinsus marinus, the causative agent of Dermo disease. In this study, we examined the N-glycans of both the hemocytes, which via CvG...
Article
Full-text available
Cancer metastasis and immune suppression are critical issues in cancer therapy. Here, we show that a β-galactoside-binding lectin [galectin-3 (gal3)] that recognizes the Thomsen-Friedenreich disaccharide (TFD, Galβ1,3GalNAc) present on the surface of most cancer cells is involved in promoting angiogenesis, tumor-endothelial cell adhesion, and metas...
Article
Full-text available
Galectins are characterized by their binding affinity for β-galactosides, a unique binding site sequence motif, and wide taxonomic distribution and structural conservation in ver-tebrates, invertebrates, protista, and fungi. Since their initial description, galectins were considered to bind endogenous ("self") glycans and mediate developmental proc...
Article
Although lectins are "hard-wired" in the germline, the presence of tandemly arrayed carbohydrate recognition domains (CRDs), of chimeric structures displaying distinct CRDs, of polymorphic genes resulting in multiple isoforms, and in some cases, of a considerable recognition plasticity of their carbohydrate binding sites, significantly expand the l...
Article
The recently described fucose-binding agglutinin from the European eel revealed a novel lectin fold (the ‘F-type’ fold) that is shared with other carbohydrate-binding proteins and proteins from prokaryotes to vertebrates clustered under the newly established F-type lectin (FTL) family. We previously reported the purification and biochemical charact...
Article
Galectins constitute an evolutionary conserved family of ß-galactoside-binding proteins, ubiquitous in mammals and other vertebrate taxa, invertebrates, and fungi. Since their discovery in the 1970s, their biological roles, initially understood as limited to recognition of carbohydrate ligands in embryogenesis and development, have expanded in rece...
Article
Protein-carbohydrate interactions mediated by lectins have been recognized as key components of innate immunity in vertebrates and invertebrates, not only for recognition of potential pathogens, but also for participating in downstream effector functions, such as their agglutination, immobilization, and complement-mediated opsonization and killing....
Article
Perkinsus marinus (Phylum Perkinsozoa) is a protozoan parasite that has devastated natural and farmed oyster populations in the USA, significantly affecting the shellfish industry and the estuarine environment. The other two genera in the phylum, Parvilucifera and Rastrimonas, are parasites of microeukaryotes. The Perkinsozoa occupies a key positio...
Article
In the past decade, increasing efforts have been devoted to the study of galectins, a family of evolutionarily conserved glycan-binding proteins with multifunctional properties. Galectins function, either intracellularly or extracellularly, as key biological mediators capable of monitoring changes occurring on the cell surface during fundamental bi...
Article
Microbial pathogens succeed in acquiring essential metals such as iron and manganese despite their limited availability because of the host's immune response. The eukaryotic natural resistance-associated macrophage proteins mediate uptake of divalent metals and, during infection, may compete directly for metal acquisition with the pathogens' transp...
Article
The plasma of the striped bass Morone saxatilis contains a fucose-specific lectin (MsaFBP32) that consists of two F-type carbohydrate recognition domains (CRDs) in tandem. The crystal structure of the complex of MsaFBP32 with l-fucose reported here shows a cylindrical 81-A-long and 60-A-wide trimer divided into two globular halves: one containing N...
Article
Full-text available
The purpose of this study was to identify secreted proteins in the retina of the adult zebrafish that are induced by the selective death of photoreceptors and to test experimentally the function of these proteins during the regeneration of photoreceptors. Induced selective death of photoreceptors in the retina of the adult zebrafish was combined wi...
Data
Perkinsus marinus EST cluster consensus and singleton sequences. This file contains Fasta-formatted files of 7,863 P. marinus EST cluster consensus and singleton sequences with the cluster ID numbers assigned in this study.
Data
Full-text available
Supplemental information for the analyses described in the text. This file contains the names of the annotated genomes used in the phylogenetic analysis, a BLASTX analysis of P. marinus EST, the number of sequences in NCBI for each taxonomic group, and the number of orthologous groups and protein sequences within each group that are shared with P....