Topic: Nuclear pore complex

Structural studies of the nuclear pore complex, conducted at Rockefeller, have revealed much about the inner workings of the huge 450-protein pore and have provided a glimpse into how the nucleus itself first evolved.

The nuclear pore complex is a protein assembly found in the membrane surrounding the cell nucleus. Consisting of multiple copies of about 30 different proteins, the nuclear pore complex is a flexible structure that transports certain molecules, including RNA, ribosomes, signal molecules, carbohydrates and lipids, across the nuclear membrane. The average vertebrate cell nucleus is studded with about 2,000 nuclear pore complexes.

Given the central role of the nuclear pore complex in the most basic cell processes, defects in its assembly, structure and function can have lethal consequences. Its proteins have been associated with viral infection, primary biliary cirrhosis and cancer. An understanding of how the complex works could lead to treatments for these diseases and also help explain the evolutionary leap that led to the development of the gene-protecting nucleus itself.

Recent research in the labs of Rockefeller University scientists Günter Blobel, Brian T. Chait and Michael P. Rout suggests that all eukaryotes share a common architecture for the nuclear pore complex and the vehicles that transport cargo between different parts of the cell, called coated vesicles. As early as 1980, Blobel proposed that the internal membranes of cells — such as those encompassing the nucleus and vesicles — evolved from invaginations of the outer cell membrane. More recently, Rout and Chait suggested that the nuclear pore complex and vesicle coats, which both contain α-solenoid and β-propeller protein folds, evolved from ancient molecules called protocoatomers that stabilized the membranes of these primordial internal structures. Research is currently underway at Rockefeller to fully detail the structure and function of the 30 proteins that make up the nuclear pore complex.