例如:"lncRNA", "apoptosis", "WRKY"

Distinct subregions of Swi1 manifest striking differences in prion transmission and SWI/SNF function.

Mol Cell Biol. 2010 Oct;30(19):4644-55. Epub 2010 Aug 02
Zhiqiang Du 1 , Emily T Crow , Hyun Seok Kang , Liming Li
Zhiqiang Du 1 , Emily T Crow , Hyun Seok Kang , Liming Li

[No authors listed]

Author information
  • 1 Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Searle 5-474, MC S205, 320 E. Superior Street, Chicago, IL 60611, USA.

摘要


We have recently reported that the yeast chromatin-remodeling factor Swi1 can exist as a prion, [SWI(+)], demonstrating a link between prionogenesis and global transcriptional regulation. To shed light on how the Swi1 conformational switch influences Swi1 function and to define the sequence and structural requirements for [SWI(+)] formation and propagation, we functionally dissected the Swi1 molecule. We show here that the [SWI(+)] prion features are solely attributable to the first 327 amino acid residues (N), a region that is asparagine rich. N was aggregated in [SWI(+)] cells but diffuse in [swi(-)] cells; chromosomal deletion of the N-coding region resulted in [SWI(+)] loss, and recombinant N peptide was able to form infectious amyloid fibers in vitro, enabling [SWI(+)] de novo formation through a simple transformation. Although the glutamine-rich middle region (Q) was not sufficient to aggregate in [SWI(+)] cells or essential for SWI/SNF function, it significantly modified the Swi1 aggregation pattern and Swi1 function. We also show that excessive Swi1 incurred Li(+)/Na(+) sensitivity and that the N/Q regions are important for this gain of sensitivity. Taken together, our results provide the final proof of "protein-only" transmission of [SWI(+)] and demonstrate that the widely distributed "dispensable" glutamine/asparagine-rich regions/motifs might have important and divergent biological functions.