Structure and function of the nuclear pore complex: new perspectives.
The double membrane of the nuclear envelope is a formidable barrier separating the nucleus and cytoplasm of eukaryotic cells. However, movement of specific macromolecules across the nuclear envelope is critical for embryonic development, cell growth and differentiation. Transfer of molecules between the nucleus and cytoplasm occurs through the aqueous channel formed by the nuclear pore complex (NPC). Although small molecules may simply diffuse across the NPC, transport of large proteins and RNA requires specific transport signals and is energy dependent. A family of pore glycoproteins modified by O-linked N-acetylglucosamine moieties are essential for transport through the NPC. Recent evidence suggests that the regulation of nuclear transport may also involve the interaction of RNA and nuclear proteins with specific binding proteins that recognize these transport signals. Are these nuclear pore glycoproteins and signal binding proteins the 'gatekeepers' that control access to the genetic material? Recent evidence obtained from a combination of biochemical and genetic approaches suggests--perhaps.
Laboratory of Biochemistry and Metabolism, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
C M
CM
Starr
J A
JA
Hanover
D000818:Animals; D005786:Gene Expression Regulation; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology*; D008954:Models, Biological; D009685:Nuclear Envelope / Q000502:physiology*; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D012313:RNA / Q000235:genetics / Q000378:metabolism
D008562:Membrane Glycoproteins; D009687:Nuclear Proteins; D012313:RNA