The pre-integration complex (PIC) is a
nucleoprotein complex of viral
genetic material
Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic aci ...
and associated viral and host proteins which is capable of inserting a viral genome into a host genome. The PIC forms after uncoating of a viral particle after entry into the host cell. In the case of the
human immunodeficiency virus
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause AIDS, acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of th ...
(HIV), the PIC forms after the Reverse Transcription Complex (RTC) has reverse transcribed the viral RNA into DNA.
The PIC consists of viral proteins (including
Vpr,
matrix
Matrix (: matrices or matrixes) or MATRIX may refer to:
Science and mathematics
* Matrix (mathematics), a rectangular array of numbers, symbols or expressions
* Matrix (logic), part of a formula in prenex normal form
* Matrix (biology), the m ...
and
integrase
Retroviral integrase (IN) is an enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme ...
), host proteins (including
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.
Function
The protein encoded by this gene was identified by its abilit ...
) and the viral DNA.
The PIC enters the cellular nucleus through the
nuclear pore complex
The nuclear pore complex (NPC), is a large protein complex giving rise to the nuclear pore. A great number of nuclear pores are studded throughout the nuclear envelope that surrounds the eukaryote cell nucleus. The pores enable the nuclear tra ...
without disrupting the
nuclear envelope
The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus, which encloses the genetic material.
The nuclear envelope consists of two lipid bilayer membran ...
, thus allowing HIV and related
retroviruses
A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase ...
to replicate in non-dividing cells. Following nuclear entry, the PIC's DNA payload may be integrated into the host
DNA
Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
as a "
provirus
A provirus is a virus genome that is integrated into the DNA of a host cell. In the case of bacterial viruses (bacteriophages), proviruses are often referred to as prophages. However, proviruses are distinctly different from prophages and these te ...
".
See also
*
HIV
*
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.
Function
The protein encoded by this gene was identified by its abilit ...
References
External links
*http://www.mcld.co.uk/hiv/?q=preintegration%20complex
*
Virology
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