Type I protein kinase a is localized to interphase microtubules and strongly associated with the mitotic spindle.
We show here that type I protein kinase A is localized to microtubules during the entire cell cycle in epithelial (hepatoma, cervical carcinoma) and nonepithelial (myoblast) cell lines. The association of the type Ialpha regulatory subunit is very strong in all phases of mitosis, from prophase to cytokinesis. In interphase, the association appears weaker, reflecting perhaps a more dynamic molecular interaction. This regulatory subunit appears to recruit catalytic subunits as the latter are also associated with microtubules. BW1J hepatoma cells, stably transfected with either wild-type or mutant Ialpha regulatory subunit, are enriched in aberrant mitoses with multipolar spindles and in mono- or multinucleated giant cells. This suggests that type I protein kinase A could have a role in centrosome duplication and/or segregation, sister chromatid separation, or cytokinesis.
Imaizumi-Scherrer
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Unité de Génétique de la Différenciation, URA du CNRS 1773, France.
Faust
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Barradeau
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Hellio
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Weiss
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MC
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002457:Cell Extracts; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D007399:Interphase; D008562:Membrane Glycoproteins; D051379:Mice; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology*; D016296:Mutagenesis; D009994:Osmolar Concentration; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism*; D016707:Tissue Fixation; D014162:Transfection; D014407:Tumor Cells, Cultured; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism
D000911:Antibodies, Monoclonal; D002457:Cell Extracts; C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins; D017868:Cyclic AMP-Dependent Protein Kinases