TY - JOUR
T1 - Identification of a human immunodeficiency virus type 1 Tat epitope that is neuroexcitatory and neurotoxic
AU - Nath, Avindra
AU - Psooy, Karen
AU - Martin, Carol
AU - Knudsen, Bodo
AU - Magnuson, David S.K.
AU - Haughey, Norman
AU - Geiger, Jonathan D.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1996
Y1 - 1996
N2 - Tat is an 86- to 104-amino-acid viral protein that activates human immunodeficiency virus type 1 expression, modifies several cellular functions, and causes neurotoxicity. Here, we determined the extent to which peptide fragments of human immunodeficiency virus type 1 BRU Tat1-86 produced neurotoxicity, increased levels of intracellular calcium ([Ca2+](i)), and affected neuronal excitability. Tat31-61 but not Tat48-85 dose dependently increased cytotoxicity and levels of [Ca2+](i) in cultured human fetal brain cells. Similarly, Tat31-61 but not Tat48-85 depolarized rat hippocampal CA1 neurons in slices of rat brain. The neurotoxicity and increases in [Ca2+](i) could be significantly inhibited by non-N-methyl-D-aspartate excitatory amino acid receptor antagonists. Shorter 15-mer peptides which overlapped by 10 amino acids each and which represented the entire sequence of Tat1-86 failed to produce any measurable neurotoxicity. Although it remains to be determined if Tat acts directly on neurons and/or indirectly via glial cells, these findings do suggest that Tat neurotoxicity is conformationally dependent, that the active site resides within the first exon of Tat between residues 31 to 61, and that these effects are mediated at least in part by excitatory amino acid receptors.
AB - Tat is an 86- to 104-amino-acid viral protein that activates human immunodeficiency virus type 1 expression, modifies several cellular functions, and causes neurotoxicity. Here, we determined the extent to which peptide fragments of human immunodeficiency virus type 1 BRU Tat1-86 produced neurotoxicity, increased levels of intracellular calcium ([Ca2+](i)), and affected neuronal excitability. Tat31-61 but not Tat48-85 dose dependently increased cytotoxicity and levels of [Ca2+](i) in cultured human fetal brain cells. Similarly, Tat31-61 but not Tat48-85 depolarized rat hippocampal CA1 neurons in slices of rat brain. The neurotoxicity and increases in [Ca2+](i) could be significantly inhibited by non-N-methyl-D-aspartate excitatory amino acid receptor antagonists. Shorter 15-mer peptides which overlapped by 10 amino acids each and which represented the entire sequence of Tat1-86 failed to produce any measurable neurotoxicity. Although it remains to be determined if Tat acts directly on neurons and/or indirectly via glial cells, these findings do suggest that Tat neurotoxicity is conformationally dependent, that the active site resides within the first exon of Tat between residues 31 to 61, and that these effects are mediated at least in part by excitatory amino acid receptors.
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U2 - 10.1128/jvi.70.3.1475-1480.1996
DO - 10.1128/jvi.70.3.1475-1480.1996
M3 - Article
C2 - 8627665
AN - SCOPUS:0030068995
VL - 70
SP - 1475
EP - 1480
JO - Journal of Virology
JF - Journal of Virology
SN - 0022-538X
IS - 3
ER -