Functionalization of a nanopore: the nuclear pore complex paradigm.
Biological cells maintain a myriad of nanopores which, although relying on the same basic small-hole principle, serve a large variety of functions. Here we consider how the nuclear pore complex (NPC), a large nanopore mediating the traffic between genetic material and protein synthesizing apparatus, is functionalized to carry out a set of transport functions. A major parameter of NPC functionalization is a lining of it external and internal surfaces with so-called phenylalanine glycine (FG) proteins. FG proteins integrate a multitude of transport factor binding sites into intrinsically disordered domains. This surprising finding has given rise to a number of transport models assigning direct gating functions to FG proteins. However, recent data suggest that the properties of FG proteins cannot be properly assessed by considering only the purified, transport-factor-stripped NPC. At physiological conditions transport factors may shape FG proteins in a way allotting an essential role to surface diffusion, reconciling tight binding with efficient transport. Thus, NPC studies are revealing both general traits and novel aspects of nanopore functionalization. In addition, they inspire artificial molecule sorters for proteomic and pharmaceutical applications.
Peters
Reiner
R
The Rockefeller University, Laboratory for mass spectrometry and gaseous ion chemistry, 1230 York Avenue, New York, NY 10065, USA. rpeters@rockefeller.edu
D021581:Active Transport, Cell Nucleus; D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D006801:Humans; D008954:Models, Biological; D049329:Nanostructures / Q000648:ultrastructure*; D022022:Nuclear Pore / Q000502:physiology* / Q000648:ultrastructure*; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry / Q000502:physiology; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology; D020449:Repetitive Sequences, Amino Acid
D028861:Nuclear Pore Complex Proteins; D018160:Receptors, Cytoplasmic and Nuclear