Pre-integration complex
Encyclopedia
The pre-integration complex (PIC) is a nucleoprotein
complex of viral genetic material and associated viral and host proteins. The PIC forms after uncoating of a viral particle after entry into the host cell. In the case of the human immunodeficiency virus
(HIV), the PIC consists of viral proteins (including Vpr
, matrix and integrase
), host proteins (including Barrier to autointegration factor 1
) and two strands of the ribonucleic acid
(RNA) genome. Within the HIV PIC, the process of reverse transcription converts the viral RNA genome into double-stranded DNA (dsDNA). The PIC enters the cellular nucleus through the nuclear pore complex without disrupting the nuclear envelope
, thus allowing HIV and related retroviruses to replicate in non-dividing cells. Following nuclear entry, the PIC's DNA payload may be integrated into the host DNA
as a "provirus
".
Nucleoprotein
A nucleoprotein is any protein that is structurally associated with nucleic acid .Many viruses harness this protein, and they are known for being host-specific...
complex of viral genetic material and associated viral and host proteins. The PIC forms after uncoating of a viral particle after entry into the host cell. In the case of the human immunodeficiency virus
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
(HIV), the PIC consists of viral proteins (including Vpr
Vpr
Vpr is a HIV gene.It stands for "Viral Protein R". Vpr, a 96 amino acid 14-kDa protein, plays an important role in regulating nuclear import of the HIV-1 pre-integration complex, and is required for virus replication in non-dividing cells such as macrophages...
, matrix and integrase
Integrase
Retroviral integrase is an enzyme produced by a retrovirus that enables its genetic material to be integrated into the DNA of the infected cell...
), host proteins (including Barrier to autointegration factor 1
Barrier to autointegration factor 1
Barrier-to-autointegration factor is a protein that in humans is encoded by the BANF1 gene. It is a member of the barrier-to-autointegration factor family of proteins. It also associates with the LEM Domain containing proteins LAP2, Emerin, and MAN1....
) and two strands of the ribonucleic acid
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
(RNA) genome. Within the HIV PIC, the process of reverse transcription converts the viral RNA genome into double-stranded DNA (dsDNA). The PIC enters the cellular nucleus through the nuclear pore complex without disrupting the nuclear envelope
Nuclear envelope
A nuclear envelope is a double lipid bilayer that encloses the genetic material in eukaryotic cells. The nuclear envelope also serves as the physical barrier, separating the contents of the nucleus from the cytosol...
, thus allowing HIV and related retroviruses to replicate in non-dividing cells. Following nuclear entry, the PIC's DNA payload may be integrated into the host DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
as a "provirus
Provirus
A provirus is a virus genome that is integrated into the DNA of a host cell.This state can be a stage of virus replication, or a state that persists over longer periods of time as either inactive viral infections or an endogenous retrovirus. In inactive viral infections the virus will not replicate...
".