Send to

Choose Destination
See comment in PubMed Commons below
J Cell Biol. 1991 Nov;115(4):919-31.

Compartmentalization within the nucleus: discovery of a novel subnuclear region.

Author information

  • 1Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.


Antibodies to a set of structurally related autoantigens (p23-25) bind to a previously uncharacterized, large structural domain in the nucleus of a variety of human cell types. This subnuclear domain is visible by phase contrast alone as a region of decreased density after several different fixation protocols. The morphology of this region changes dramatically during the cell cycle and we have given it the name PIKA (for polymorphic interphase karyosomal association) based on preliminary evidence that the PIKA proteins may be associated with chromatin. The function of the PIKA is not yet known, but our immunolocalization data indicate that it is unlikely to be associated with regions of ongoing DNA replication, heterogeneous nuclear RNA storage, or mRNA processing. The discovery of the PIKA provides evidence supporting an emerging model of nuclear structure. It now appears that the nucleus is organized into distinct domains which include not only the nucleolus, but also previously unidentified regions such as the PIKAs. Furthermore, structural rearrangements undergone by the nucleolus and the PIKAs may be indicative of a broad tendency for nuclear organization to change in a cell cycle-specific fashion.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center