A viral tegument or tegument, more commonly known as a viral matrix, is a cluster of proteins that lines the space between the envelope and nucleocapsid of all herpesviruses

Herpesviridae

The Herpesviridae are a large family of DNA viruses that cause diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word herpein , referring to the latent, recurring infections typical of this group of viruses...

. The tegument generally contains proteins that aid in viral DNA replication

DNA replication

DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance. The process starts with one double-stranded DNA molecule and produces two identical copies of the molecule...

 and evasion of the immune response, typically with inhibition of signalling in the immune system and activation of interferon

Interferon

Interferons are proteins made and released by host cells in response to the presence of pathogens—such as viruses, bacteria, or parasites—or tumor cells. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.IFNs belong to...

s. The tegument is usually released shortly after infection into the cytoplasm

Cytoplasm

The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

. These proteins are usually formed within the late phase of the viral infectious cycle, after viral genes have been replicated. Much information regarding viral teguments has been gathered from studying Herpes simplex virus

Herpes simplex virus

Herpes simplex virus 1 and 2 , also known as Human herpes virus 1 and 2 , are two members of the herpes virus family, Herpesviridae, that infect humans. Both HSV-1 and HSV-2 are ubiquitous and contagious...

.

Properties of teguments

Viral teguments can be symmetrically arranged via structural and scaffolding protein or can also be asymmetric

Asymmetric

Something which is asymmetric displays asymmetry. Specific uses of the term may include:*Asymmetric relation for information on such relations in mathematics and set theory*Asymmetric warfare for information and theories of modern war...

ally arranged, depending on the virus. Teguments are rarely haphazardly placed and usually involve scaffolding proteins in their formation around the nucleocapsid. Non-essential proteins included in the tegument may aid in immune response suppression, suppression of host mRNA transcription

Transcription (genetics)

Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

 or suppression of intrinsic or cellular defenses. Essential proteins will include factors that help in either recruiting host transcription or translation factors, or directly transcribing or translating viral genes. Tegumental contents are released into the cytoplasm upon entrance into the cell upon which many tegumental proteins become active. The tegument may also aid in insertion of the viral genome into host cell cytoplasm or nucleus.

Viruses containing teguments

Teguments are generally in enveloped viruses which have nucleocapsids, as tegument proteins cannot be stored in an efficient fashion in capsid-only viruses. Many DNA viruses also have teguments because DNA viruses often need to package their own proteases and polymerases to begin viral transcription. The best studied examples are the Herpesvirus family, in which the tegument is most prominent.