The two zinc fingers in the human immunodeficiency virus type 1 nucleocapsid protein are not functionally equivalent
Autor: | Louis E. Henderson, Robert J. Gorelick, L O Arthur, D J Chabot, Alan Rein |
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Rok vydání: | 1993 |
Předmět: |
viruses
Molecular Sequence Data Immunology Mutant Gene Products gag Mutagenesis (molecular biology technique) RNA-binding protein Biology Transfection Virus Replication gag Gene Products Human Immunodeficiency Virus Microbiology Virus Structure-Activity Relationship Viral Proteins Virology Humans Amino Acid Sequence Peptide sequence Zinc finger Base Sequence RNA-Binding Proteins RNA Zinc Fingers Molecular biology Microscopy Electron Oligodeoxyribonucleotides Viral replication Insect Science HIV-1 Mutagenesis Site-Directed RNA Viral Capsid Proteins HeLa Cells Research Article |
Zdroj: | Journal of Virology. 67:4027-4036 |
ISSN: | 1098-5514 0022-538X |
Popis: | The highly conserved zinc fingers in retroviral nucleocapsid (NC) proteins have the general structure Cys-(X)2-Cys-(X)4-His-(X)4-Cys. Human immunodeficiency virus type 1 (HIV-1) contains two Zn2+ fingers, and mutants were constructed in which the native sequence of each Zn2+ finger was maintained but their positions in the NC protein were changed. Mutants had either two first-finger sequences (pNC1/1), two second-finger sequences (pNC2/2), or reversed first- and second-finger sequences (pNC2/1). Cells transfected with mutant or wild-type clones produced similar levels of Tat, Gag, Pol, and Env proteins, formed syncytia, and shed viruslike particles that were indistinguishable by electron microscopy. However, the pNC2/1 and pNC2/2 mutants were inefficient in packaging genomic RNA (less than 15% of wild-type levels), whereas the pNC1/1 mutant packaged approximately 70% of wild-type levels of RNA. No infectious virus could be detected with either the pNC2/1 or pNC2/2 mutants, whereas the pNC1/1 mutant appeared to sustain a low level of replication and reverted to a competent wild-type-like viral species after a 2- to 4-week lag period. The data strongly suggest that the two Zn2+ fingers of HIV-1 are not functionally equivalent and that the first Zn2+ finger in the Gag precursor plays a more prominent role in RNA selection and packaging. The data also indicate that both Zn2+ fingers in the mature NC protein play as yet unknown roles in viral assembly or the early stages of the viral infection process. |
Databáze: | OpenAIRE |
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