Vinnexin is a

transmembrane protein A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...

whose DNA code is held in a

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

. When the virus genome is expressed in a

cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...

the vinnexin gene from the virus is made into a functioning protein by the infected cell. The vinnexin protein is then incorporated into the host's

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

s to alter the way the hosts cells communicate with each other. The altered communication aids the transmission and replication of the virus in complex ways. The communication structure that the vinnexin is involved in is the

gap junction Gap junctions are specialized intercellular connections between a multitude of animal cell-types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulate ...

and vinnexin forms part of a wider family of proteins that are innexin homologues referred to as

pannexin Pannexins (from Greek 'παν' — all, and from Latin 'nexus' — connection) are a family of vertebrate proteins identified by their homology to the invertebrate innexins. While innexins are responsible for forming gap junctions in invertebr ...

s. So far Vinnexins have only been found in Adenovirus and the way they affect the functioning of innexins is being studied in great detail.

Discovery

Vinnexin was first described in 2005 in an

adenovirus Adenoviruses (members of the family ''Adenoviridae'') are medium-sized (90–100 nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from the ...

as a gene homologue of an insect gap protein called

innexin Innexins are transmembrane proteins that form gap junctions in invertebrates. Gap junctions are composed of membrane proteins that form a channel permeable to ions and small molecules connecting the cytoplasm of adjacent cells. Although gap junct ...

Vinnexins were shown to be used by the adenovirus to help Incheon wasps successfully inject there eggs into the caterpillars they parasitize.

Structure

The ultrastructure of Vinnexin is yet to be studied in detail. As an innexin homologue that functions in a similar way to innexins vinnexins are likely to have four transmembrane segments (TMSs) and, like the vertebrate

connexin Connexins (Cx)TC# 1.A.24, or gap junction proteins, are structurally related transmembrane proteins that assemble to form vertebrate gap junctions. An entirely different family of proteins, the innexins, form gap junctions in invertebrates. Each ...

gap junction protein, vinnexin subunits assemble together to form a channel in the

plasma membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (t ...

of the cell. Connexin

Function

Fundamentally vinnexins have been shown to behave like the native innexins in insects. They participate in gap junctions to form transmembrane communication channels. At a higher level vinnexins must differ sufficiently from native innexins to alter the way the caterpillar host cells behave. Without the virus with its vinnexin gene the egg of certain wasps would be rejected by the caterpillar and the egg would die. The virus and wasp are obligately associated Cotesia glomerata (NZAC06000976)

While the virus genes are expressed in the caterpillar the viral DNA including the vinnexin gene does not replicate its genes there. Replication of the virus including the vennexin gene occurs in the ovaries of the wasp.

Transport reaction

The transport reactions catalyzed by innexin gap junctions which are considered similar to vinnexins are: :Small molecules (cell 1 cytoplasm) ⇌ small molecules (cell 2 cytoplasm) Or for hemichannels: :Small molecules (cell cytoplasm) ⇌ small molecules (out)

Discovery

Structure

Function

Transport reaction

See also

References

Further reading