Single particle imaging of mRNAs crossing the nuclear pore: Surfing on the edge.
Six years ago, the Singer lab published a landmark paper which described how individual mRNA particles cross the nuclear pore complex in mammalian tissue culture cells. This involved the simultaneous imaging of mRNAs, each labeled by a large number of tethered fluorescent proteins and fluorescently tagged nuclear pore components. Now two groups have applied this technique to the budding yeast Saccharomyces cerevisiae. Their results indicate that in the course of nuclear export, mRNAs likely engage complexes that are present on either side of the pore and that these interactions are modulated by proteins present in the messenger ribonucleoprotein (mRNP) complex. These findings lend support to the notion that just before and/or after the completion of nuclear export, mRNPs undergo one or more maturation steps that prepare the packaged mRNAs for translation. These results represent new and exciting insights into the mechanism of mRNA nuclear export.
Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
Alexander F
AF
Palazzo
Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
Mathew
M
Truong
D021581:Active Transport, Cell Nucleus; D008856:Microscopy, Fluorescence; D022022:Nuclear Pore / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D034443:RNA Transport; D012333:RNA, Messenger / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
D009687:Nuclear Proteins; D012333:RNA, Messenger; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C026452:messenger ribonucleoprotein
fluorescently-tagged mRNA; high resolution fluorescence microscopy; mRNA export; mRNP maturation; mRNP quality control; nuclear pore complex; single particle tracking