Premium
Stress responses of PML nuclear domains are ablated by ataxin‐1 and other nucleoprotein inclusions
Author(s) -
Dovey Claire L,
Varadaraj Archana,
Wyllie Andrew H,
Rich Tina
Publication year - 2004
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1604
Subject(s) - promyelocytic leukemia protein , nuclear protein , nucleoprotein , neurodegeneration , microbiology and biotechnology , polyglutamine tract , biology , cell nucleus , nuclear pore , heat shock protein , nucleus , mutant , genetics , virus , gene , medicine , huntingtin , pathology , transcription factor , disease
The polyglutamine diseases are characterized by expansion of triplet CAG repeats that encode polyglutamine tracts in otherwise unrelated proteins. One plausible explanation for the neurodegeneration of these disorders proposes that inclusions of such proteins sequester other significant nuclear proteins in inactive form. The present study shows that PML protein is sequestered by inclusions of the pathogenic mutant form of the polyglutamine protein ataxin‐1 and that this sequestration removes from the nucleus the free 0.2–1 µm diameter PML nuclear domains (PML‐NDs), together with at least one of their many cargo proteins (Sp100). The present study demonstrates that this sequestration can be effected equally by another nuclear protein, RED, which lacks a polyglutamine tract, but expresses a polar zipper repeat. The sequestered PML‐NDs no longer respond to stress signals (heat shock or ionizing radiation) to which they are normally sensitive. In both cases, there is independent evidence that the cells initiate other responses to their injury (nuclear translocation of heat shock protein or generation of gamma‐H2AX‐rich nuclear foci, respectively). The data thus provide strong evidence that multiple species of nuclear inclusion functionally sequester PML‐NDs. This mechanism is likely to distort cellular responses to injury of many different types. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.