Self-association of coilin reveals a common theme in nuclear body localization.
We have found that coilin, the marker protein for Cajal bodies (coiled bodies, CBs), is a self-interacting protein, and we have mapped the domain responsible for this activity to the amino-terminus. Together with a nuclear localization signal, the self-interaction domain is necessary and sufficient for localization to CBs. Overexpression of various wild-type and mutant coilin constructs in HeLa cells results in disruption of both CBs and survival motor neurons (SMN) gems. Additionally, we have identified a cryptic nucleolar localization signal (NoLS), within the coilin protein, which may be exposed in specific coilin phospho-isoforms. The implications of these findings are discussed in light of the fact that other proteins known to localize within nuclear bodies (e. g., PML, SMN and Sam68) can also self-associate. Thus protein self-interaction appears to be a general feature of nuclear body marker proteins.
Hebert
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MD
Department of Genetics, Center for Human Genetics and Program in Cell Biology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio 44106-4955, USA.
Matera
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AG
D002466:Cell Nucleolus / Q000378:metabolism; D020541:Coiled Bodies / Q000378:metabolism*; D004252:DNA Mutational Analysis; D006367:HeLa Cells; D006801:Humans; D009154:Mutation; D019913:Nuclear Localization Signals; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D014162:Transfection
D019913:Nuclear Localization Signals; D009687:Nuclear Proteins; C068921:p80-coilin; D010768:Phosphoserine