Cloning and functional characterization of the smooth muscle ether-a-go-go-related gene K+ channel. Potential role of a conserved amino acid substitution in the S4 region. Vol. 278 (2003) 2503-2514

The major virulence determinant of the rodent malaria parasite,Plasmodium yoelii, has remained unresolved since the discovery of the lethal line in the 1970s. Because virulence in this parasite correlates with the ability to invade different types of erythrocytes, we evaluated the potential role of the parasite erythrocyte binding ligand,PyEBL. We found 1 amino acid substitution in a domain responsible for intracellular trafficking between the lethal and nonlethal parasite lines and, furthermore, that the intracellular localization ofPyEBL was distinct between these lines. Genetic modification showed that this substitution was responsible not only forPyEBL localization but also the erythrocyte-type invasion preference of the parasite and subsequently its virulence in mice. This previously unrecognized mechanism for altering an invasion phenotype indicates that subtle alterations of a malaria parasite ligand can dramatically affect host–pathogen interactions and malaria virulence.

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Expression and Functional Characterization of the Human Ether-à-go-go-Related Gene (HERG) K+ Channel Cardiac Splice Variant in Xenopus laevis Oocytes

The Journal of Membrane Biology ◽

10.1007/s00232-006-0010-9 ◽

2006 ◽

Vol 211 (2) ◽

pp. 115-126 ◽

Cited By ~ 5

Author(s):

Ebru Aydar ◽

Christpher Palmer

Keyword(s):

Xenopus Laevis ◽

Splice Variant ◽

Functional Characterization ◽

K Channel ◽

Xenopus Laevis Oocytes ◽

Related Gene

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Expression and Functional Characterization of the Agrobacterium VirB2 Amino Acid Substitution Variants in T-pilus Biogenesis, Virulence, and Transient Transformation Efficiency

PLoS ONE ◽

10.1371/journal.pone.0101142 ◽

2014 ◽

Vol 9 (6) ◽

pp. e101142 ◽

Cited By ~ 6

Author(s):

Hung-Yi Wu ◽

Chao-Ying Chen ◽

Erh-Min Lai

Keyword(s):

Amino Acid ◽

Amino Acid Substitution ◽

Transformation Efficiency ◽

Functional Characterization ◽

Transient Transformation ◽

Pilus Biogenesis

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Isolation and Functional Characterization of Primary Cultures of Vascular Smooth Muscle Cells from Congenic Rats for the Different Subunits of Adducin

High Blood Pressure & Cardiovascular Prevention ◽

10.2165/00151642-200512030-00142 ◽

2005 ◽

Vol 12 (3) ◽

pp. 185

Author(s):

R. Sallo ◽

L. Contini ◽

A. Pende ◽

G. Lotti

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Primary Cultures ◽

Functional Characterization ◽

Muscle Cells

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Specificity of the HIV-1 Protease on Substrates Representing the Cleavage Site in the Proximal Zinc-Finger of HIV-1 Nucleocapsid Protein

Viruses ◽

10.3390/v13061092 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1092

Author(s):

János András Mótyán ◽

Márió Miczi ◽

Stephen Oroszlan ◽

József Tőzsér

Keyword(s):

Amino Acid ◽

Zinc Finger ◽

Cleavage Site ◽

Potential Role ◽

Binding Mode ◽

Interaction Energies ◽

Vitro Assay ◽

Hiv 1

To explore the sequence context-dependent nature of the human immunodeficiency virus type 1 (HIV-1) protease’s specificity and to provide a rationale for viral mutagenesis to study the potential role of the nucleocapsid (NC) processing in HIV-1 replication, synthetic oligopeptide substrates representing the wild-type and modified versions of the proximal cleavage site of HIV-1 NC were assayed as substrates of the HIV-1 protease (PR). The S1′ substrate binding site of HIV-1 PR was studied by an in vitro assay using KIVKCF↓NCGK decapeptides having amino acid substitutions of N17 residue of the cleavage site of the first zinc-finger domain, and in silico calculations were also performed to investigate amino acid preferences of S1′ site. Second site substitutions have also been designed to produce “revertant” substrates and convert a non-hydrolysable sequence (having glycine in place of N17) to a substrate. The specificity constants obtained for peptides containing non-charged P1′ substitutions correlated well with the residue volume, while the correlation with the calculated interaction energies showed the importance of hydrophobicity: interaction energies with polar residues were related to substantially lower specificity constants. Cleavable “revertants” showed one residue shift of cleavage position due to an alternative productive binding mode, and surprisingly, a double cleavage of a substrate was also observed. The results revealed the importance of alternative binding possibilities of substrates into the HIV-1 PR. The introduction of the “revertant” mutations into infectious virus clones may provide further insights into the potential role of NC processing in the early phase of the viral life-cycle.

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