Molecular and functional characterization of two infectious salmon anaemia virus (ISAV) proteins with type I interferon antagonizing activity

ABSTRACT Efficient and specific host cell entry is of exquisite importance for intracellular pathogens. Parasites of the phylum Apicomplexa are highly motile and actively enter host cells. These functions are mediated by type I transmembrane invasins of the TRAP family that link an extracellular recognition event to the parasite actin-myosin motor machinery. We systematically tested potential parasite invasins for binding to the actin bridging molecule aldolase and complementation of the vital cytoplasmic domain of the sporozoite invasin TRAP. We show that the ookinete invasin CTRP and a novel, structurally related protein, termed TRAP-like protein (TLP), are functional members of the TRAP family. Although TLP is expressed in invasive stages, targeted gene disruption revealed a nonvital role during life cycle progression. This is the first genetic analysis of TLP, encoding a redundant TRAP family invasin, in the malaria parasite.

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Evaluation of an enzyme immunoassay kit for estrogen receptor measurement--report II.

Clinical Chemistry ◽

10.1093/clinchem/34.10.2053 ◽

1988 ◽

Vol 34 (10) ◽

pp. 2053-2057 ◽

Cited By ~ 2

Author(s):

S Raam ◽

D M Vrabel

Keyword(s):

Enzyme Immunoassay ◽

Binding Sites ◽

Solid Phase ◽

Functional Characterization ◽

Quantitative Agreement ◽

Type I ◽

Type Ii ◽

Immunoreactive Protein ◽

Estrogen Binding

Abstract We present evidence to show that monoclonal antibodies to estrogen receptors (ER) in solid phase recognize the secondary estrogen binding sites with moderate to low affinity for estradiol (E2). An excellent quantitative agreement was found in five cytosols between the ER values obtained by the enzyme immunoassay (ER-EIA) and the amount of secondary estrogen binding sites measured by the assay involving dextran-coated charcoal (Clin Chem 1986;32:1496). The immunoreactive protein recognized by the antibody-coated beads, when allowed to react with ER(+) cytosols, is shown to bind [3H]estradiol only when the ligand concentration exceeds 8 nmol/L. Further biochemical and functional characterization of the immunoreactive protein is required to establish similarities/dissimilarities between this protein, high-affinity Type I ER sites, and the secondary sites such as Type II sites.

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Molecular Characterization of Feline Type I Interferon Receptor 2

Journal of Interferon & Cytokine Research ◽

10.1089/jir.2009.0031 ◽

2010 ◽

Vol 30 (2) ◽

pp. 81-88 ◽

Cited By ~ 7

Author(s):

Qinghua Xue ◽

Limin Yang ◽

Xiaoling Liu ◽

Wenjun Liu

Keyword(s):

Molecular Characterization ◽

Type I Interferon ◽

Type I ◽

Interferon Receptor

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361 Characterization of the bovine Type I interferon locus

Cytokine ◽

10.1016/j.cyto.2008.07.446 ◽

2008 ◽

Vol 43 (3) ◽

pp. 329

Author(s):

Angela Walker ◽

R. Michael Roberts

Keyword(s):

Type I Interferon ◽

Type I ◽

Bovine Type

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Characterization of gene expression on genomic segment 7 of infectious salmon anaemia virus

Virology Journal ◽

10.1186/1743-422x-4-34 ◽

2007 ◽

Vol 4 (1) ◽

pp. 34 ◽

Cited By ~ 24

Author(s):

Frederick SB Kibenge ◽

Hongtao Xu ◽

Molly JT Kibenge ◽

Biao Qian ◽

Tomy Joseph

Keyword(s):

Gene Expression ◽

Infectious Salmon Anaemia Virus ◽

Genomic Segment ◽

Infectious Salmon Anaemia

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Mammalian Casein Kinase 1α and Its Leishmanial Ortholog Regulate Stability of IFNAR1 and Type I Interferon Signaling

Molecular and Cellular Biology ◽

10.1128/mcb.00478-09 ◽

2009 ◽

Vol 29 (24) ◽

pp. 6401-6412 ◽

Cited By ~ 51

Author(s):

Jianghuai Liu ◽

Lucas P. Carvalho ◽

Sabyasachi Bhattacharya ◽

Christopher J. Carbone ◽

K. G. Suresh Kumar ◽

...

Keyword(s):

Er Stress ◽

Mammalian Cells ◽

Leishmania Major ◽

Type I Interferon ◽

Casein Kinase ◽

Type I ◽

Bona Fide ◽

Activity Dependent

ABSTRACT Phosphorylation of the degron of the IFNAR1 chain of the type I interferon (IFN) receptor triggers ubiquitination and degradation of this receptor and, therefore, plays a crucial role in negative regulation of IFN-α/β signaling. Besides the IFN-stimulated and Jak activity-dependent pathways, a basal ligand-independent phosphorylation of IFNAR1 has been described and implicated in downregulating IFNAR1 in response to virus-induced endoplasmic reticulum (ER) stress. Here we report purification and characterization of casein kinase 1α (CK1α) as a bona fide major IFNAR1 kinase that confers basal turnover of IFNAR1 and cooperates with ER stress stimuli to mediate phosphorylation-dependent degradation of IFNAR1. Activity of CK1α was required for phosphorylation and downregulation of IFNAR1 in response to ER stress and viral infection. While many forms of CK1 were capable of phosphorylating IFNAR1 in vitro, human CK1α and L-CK1 produced by the protozoan Leishmania major were also capable of increasing IFNAR1 degron phosphorylation in cells. Expression of leishmania CK1 in mammalian cells stimulated the phosphorylation-dependent downregulation of IFNAR1 and attenuated its signaling. Infection of mammalian cells with L. major modestly decreased IFNAR1 levels and attenuated cellular responses to IFN-α in vitro. We propose a role for mammalian and parasite CK1 enzymes in regulating IFNAR1 stability and type I IFN signaling.

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Characterization of Functional Human Skeletal Myotubes and Neuromuscular Junction Derived—From the Same Induced Pluripotent Stem Cell Source

Bioengineering ◽

10.3390/bioengineering7040133 ◽

2020 ◽

Vol 7 (4) ◽

pp. 133

Author(s):

Xiufang Guo ◽

Agnes Badu-Mensah ◽

Michael C. Thomas ◽

Christopher W. McAleer ◽

James J. Hickman

Keyword(s):

Stem Cell ◽

Pluripotent Stem Cell ◽

Disease Modeling ◽

Neuromuscular Junctions ◽

Functional Characterization ◽

Induced Pluripotent Stem Cell ◽

Patient Specific ◽

Type I ◽

Induced Pluripotent

In vitro generation of functional neuromuscular junctions (NMJs) utilizing the same induced pluripotent stem cell (iPSC) source for muscle and motoneurons would be of great value for disease modeling and tissue engineering. Although, differentiation and characterization of iPSC-derived motoneurons are well established, and iPSC-derived skeletal muscle (iPSC-SKM) has been reported, there is a general lack of systemic and functional characterization of the iPSC-SKM. This study performed a systematic characterization of iPSC-SKM differentiated using a serum-free, small molecule-directed protocol. Morphologically, the iPSC-SKM demonstrated the expression and appropriate distribution of acetylcholine, ryanodine and dihydropyridine receptors. Fiber type analysis revealed a mixture of human fast (Type IIX, IIA) and slow (Type I) muscle types and the absence of animal Type IIB fibers. Functionally, the iPSC-SKMs contracted synchronously upon electrical stimulation, with the contraction force comparable to myofibers derived from primary myoblasts. Most importantly, when co-cultured with human iPSC-derived motoneurons from the same iPSC source, the myofibers contracted in response to motoneuron stimulation indicating the formation of functional NMJs. By demonstrating comparable structural and functional capacity to primary myoblast-derived myofibers, this defined, iPSC-SKM system, as well as the personal NMJ system, has applications for patient-specific drug testing and investigation of muscle physiology and disease.

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