Nuclear Pore Complex may have started as a membrane-folding protein
In “A Structural Analysis of Eukaryotic Membrane Evolution“, the authors argue that the Nuclear Pore Complex, which is a “gatekeeper molecule” that controls what proteins can make it into and out of the nucleus of a eukaryote, may have originally been a membrane folding protein. Folded membranes are very important to Eukaryotes, who use them for practically all their organelles. While prokaryotes largely do not posess organelles, a folded interior membrane is still important for cyanobacteria, who use them to boost the surface area capable of undergoing photosynthesis. This provides an insight into the evolution of the Nuclear Pore Complex, a molecular structure that is extraordinarily complex and completely unnecessary for prokaryotes. The take-home lesson is exaptation is a major driver of evolution, and one that helps explain seemingly miraculous leaps in organismal design.