PEX3PEX16

PEX3PEX16 is a term used in discussions of peroxisome biogenesis to denote a fusion construct that combines the peroxisomal membrane proteins PEX3 and PEX16 into a single polypeptide. It is primarily considered in theoretical discussions and synthetic biology contexts rather than as a naturally occurring protein.

In eukaryotic cells, PEX3 and PEX16 are essential components of the peroxisomal membrane that coordinate the early steps of peroxisome formation. PEX3 acts as a membrane receptor for PEX19 and contributes to the docking of peroxisomal membrane proteins, while PEX16 participates in the initial targeting and assembly of peroxisomal components. The two proteins interact to organize the peroxisomal membrane surface and support membrane biogenesis and peroxisome proliferation.

A PEX3PEX16 fusion would involve linking the domains of PEX3 and PEX16 into a single polypeptide, with considerations for the topology, orientation, and linker length to preserve functional domains. The fusion protein could be designed to localize to peroxisomal membranes and potentially recruit PEX19 and other components, offering a way to test whether the PEX3–PEX16 interface is sufficient to drive aspects of membrane assembly.

In practice, PEX3PEX16 discussions emphasize potential benefits for dissecting the modular nature of peroxisome biogenesis, as well as possible drawbacks such as misfolding, improper localization, or altered regulation compared with the separate proteins. There are no widely established natural examples of such a fusion, and any experimental use would be tightly controlled and exploratory.

See also: PEX3, PEX16, peroxisome biogenesis, peroxins, PEX19.