NR AFUO
AU Inoue,Y.; Kishimoto,A.; Hirao,J.; Yoshida,M.; Taguchi,H.
TI Strong growth polarity of yeast prion fiber revealed by single fiber imaging
QU The Journal of Biological Chemistry 2001 Sep 21; 276(38): 35227-30
PT journal article
AB Using the yeast prion as a model, we have developed a novel system to observe the growth of individual prion fibers directly. NM fragments, the prion-determining region of the yeast protein Sup35p, were labeled by either red or green fluorescent dyes, and the fiber growth was observed under a fluorescence microscope. When green-Sup35NM was added to the preformed fibers made of red-Sup35NM, 70-97% of green fibers grew unidirectionally, from only one end of individual red fibers, whereas the remainder grew from both ends. Similarly, the majority of red fibers grew from only one end of green fibers when the order of addition was reversed. Sonication of preformed fibers to expose fresh ends did not change the results, excluding a possibility of occasional deformation of one end as the reason of the apparent unidirectional growth. These results indicate the polarity of Sup35 prion fibers and impose constraints on the models of fiber growth.
MH Base Sequence; DNA Primers; Fungal Proteins/metabolism; Microscopy, Fluorescence; Prions/*physiology; Saccharomyces cerevisiae/*metabolism; Support, Non-U.S. Gov't
AD Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan.
SP englisch
PO USA