Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Cell Biol. 1996 Dec;135(6 Pt 1):1457-70.

A novel ubiquitin-like modification modulates the partitioning of the Ran-GTPase-activating protein RanGAP1 between the cytosol and the nuclear pore complex.

Author information

  • 1Laboratory of Cell Biology, Howard Hughes Medical Institute, Rockefeller University, New York, NY 10021, USA.

Abstract

Ran is a nuclear Ras-like GTPase that is required for the bidirectional transport of proteins and ribnucleoproteins across the nuclear pore complex (NPC). A key regulator of the Ran GTP/GDP cycle is the 70-kD Ran-GTPase-activating protein RanGAP1. Here, we report the identification and localization of a novel form of RanGAP1. Using peptide sequence analysis and specific mAbs, RanGAP1 was found to be modified by conjugation to a ubiquitin-like protein. Immunoblot analysis and immunolocalization by light and EM demonstrated that the 70-kD unmodified from of RanGAP1 is exclusively cytoplasmic, whereas the 90-kD modified form of RanGAP1 is associated with the cytoplasmic fibers of the NPC. The modified form of RanGAP1 also appeared to associated with the mitotic spindle apparatus during mitosis. These findings have specific implications for Ran function and broad implications for protein regulation by ubiquitin-like modifications. Moreover, the variety and function of ubiquitin-like protein modifications in the cell may be more diverse than previously realized.

PMID:
8978815
[PubMed - indexed for MEDLINE]
PMCID:
PMC2133973
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk