Covalent modification of the homeodomain-interacting protein kinase 2 (HIPK2) by the ubiquitin-like protein SUMO-1.

Posttranslational modifications such as ubiquitination and phosphorylation play an important role in the regulation of cellular protein function. Homeodomain-interacting protein kinase 2 (HIPK2) is a member of the recently identified family of nuclear protein kinases that act as corepressors for homeodomain transcription factors. Here, we show that HIPK2 is regulated ...
by a ubiquitin-like protein, SUMO-1. We demonstrate that HIPK2 localizes to nuclear speckles (dots) by means of a speckle-retention signal. This speckle-retention signal contains a domain that interacts with a mouse ubiquitin-like protein conjugating (E2) enzyme, mUBC9. In cultured cells, HIPK2 is covalently modified by SUMO-1, and the SUMO-1 modification of HIPK2 correlates with its localization to nuclear speckles (dots). Thus, our results provide firm evidence that the nuclear protein kinase HIPK2 can be covalently modified by SUMO-1, which directs its localization to nuclear speckles (dots).
Mesh Terms:
Amino Acid Sequence, Animals, Base Sequence, Carrier Proteins, Cell Line, DNA Primers, Humans, Immunohistochemistry, Ligases, Mice, Molecular Sequence Data, Protein Kinases, Protein-Serine-Threonine Kinases, SUMO-1 Protein, Sequence Homology, Amino Acid, Ubiquitin-Conjugating Enzymes, Ubiquitins
Proc. Natl. Acad. Sci. U.S.A.
Date: Oct. 26, 1999
Download Curated Data For This Publication
12631
Switch View:
  • Interactions 2