Comparative proteomic analyses of the nuclear envelope and pore complex suggests a wide range of heretofore unexpected functions.
Since the discovery of several inherited diseases linked to the nuclear envelope the number of functions ascribed to this subcellular organelle has skyrocketed. However the molecular pathways underlying these functions are not clear in most cases, perhaps because of missing components. Several recent proteomic analyses of the nuclear envelope and nuclear pore complex proteomes have yielded not only enough missing components to potentially elucidate these pathways, but suggest an exponentially greater number of functions at the nuclear periphery than ever imagined. Many of these functions appear to derive from recapitulation of pathways utilized at the plasma membrane and from other membrane systems. Additionally, many proteins identified in the comparative nuclear envelope studies have sequence characteristics suggesting that they might also contribute to nuclear pore complex functions. In particular, the striking enrichment for proteins in the nuclear envelope fractions that carry phenylalanine-glycine (FG) repeats may be significant for the mechanism of nuclear transport. In retrospect, these findings are only surprising in context of the notion held for many years that the nuclear envelope was only a barrier protecting the genome. In fact, it is arguably the most complex membrane organelle in the cell.
Batrakou
Dzmitry G
DG
Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, UK.
Kerr
Alastair R W
AR
Schirmer
Eric C
EC
D000818:Animals; D005656:Fungal Proteins / Q000032:analysis; D006801:Humans; D009685:Nuclear Envelope / Q000378:metabolism*; D022022:Nuclear Pore / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000032:analysis*; D020543:Proteome / Q000032:analysis*
D005656:Fungal Proteins; D028861:Nuclear Pore Complex Proteins; D020543:Proteome