NUCLEAR DOMAIN-10 (ND10) ASSOCIATED PROTEINS ARE ALSO PRESENT IN NUCLEAR-BODIES AND REDISTRIBUTE TO HUNDREDS OF NUCLEAR SITES AFTER STRESS

The promyelocytic leukemia protein fused to the retinoic acid receptor ct in t(15;17) acute promyelocytic leukemia, the primary biliary cirr hosis autoantigen, Sp100, as well as the incompletely characterized pr otein NDP55, are co-localized in specific immunohistochemically define d nuclear domains (ND10), which are potential equivalents of ultrastru cturally defined nuclear bodies. We investigated whether the distribut ion of these proteins depends on environmental conditions and whether ND10 correlate with nuclear bodies. Certain nuclear bodies and ND10 re act in a similar way and share antigens. Interferon exposure doubled t he number of ND10 and increased the frequency of nuclear bodies, where as herpes simplex virus infection or heat shock modify both. Redistrib ution of ND10-associated proteins to hundreds of small sites throughou t the chromatin was inducible by stress in the form of heat shock and exposure to Cd++ ions. The change of distribution was rapid and indepe ndent of protein synthesis, and thus not part of the classical heat sh ock response. The very rapid redistribution of these proteins after he at shock, together with the development of ND10 upon interferon activa tion, raises the possibility that ND10 represent storage sites of cert ain matrix proteins readily accessible throughout the chromatin in res ponse to stress or other effecters that induce global nuclear changes. (C) 1995 Wiley-Liss, Inc.