Vinnexin

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 gap junction protein, vinnexin subunits assemble together to form a channel in the plasma membrane of the cell.

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.

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)