![How Nuclear Pore Traffic Cops Do Their Job]()
The nuclear envelope of eukaryotic cells must be permeable — messenger RNA molecules must exit the nucleus to be translated into proteins in the cytoplasm, for example, and newly translated chromatin protein must enter the nucleus to help form chromosomes. This two-way traffic passes through gatekeepers known as nuclear pore complexes endowed with the paradoxical ability to transport thousands of molecules both rapidly and very specifically (i.e., allowing some molecules through while blocking others). To discover the secret to the nuclear pore complexes’ success, David Cowburn, Ph.D., and collaborators looked at interactions between transiting molecules and intrinsically disordered proteins (IDPs) that line the pore’s central channel. Surprisingly, in a report published online on January 26 in the Journal of Biological Chemistry,the binding between IDPs and transiting molecules is energetically weak, allowing for rapid interactions. Simultaneously, the many phenylalanine-glycine repeats within the IDPs makes for more frequent contacts between IDPs and transiting molecule, enhancing specificity. In the February 8 online issue of Structure, Dr. Cowburn and colleagues used neutron scattering experiments to gain insights into the conformational changes that IDPs undergo. Dr. Cowburn is a professor of biochemistry and of physiology & biophysics at Einstein. Samuel Sparks, a Ph.D. student in Dr. Cowburn’s lab, was co-first author of the Journal of Biological Chemistry paper and first author of the Structure paper.
Posted on: Monday, March 05, 2018