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Plakophilin, armadillo repeats, and nuclear localization
Plakophilin, armadillo repeats, and nuclear localization.
20
Plakophilins are armadillo-repeat containing proteins, identified through their localization to desmosomes. Expressed in a wide range of tissues, plakophilins are largely nuclear in most cell types [Schmidt et al. (1997) Cell Tissue Res 290:481; Mertens et al. (1996) J. Cell Biol 135:1009]. Using Xenopus embryos and cultured A6 cells, together with myc- and green fluorescent protein (GFP)-tags, we found that both the N-terminal, non-armadillo repeat head and the C-terminal armadillo repeat-containing regions can enter nuclei. The arm repeat domain is predominantly cytoplasmic and concentrated at the cell cortex, whereas the head and full-length polypeptides are concentrated in the nucleus. The head domain can also be seen to decorate and disrupt keratin filament network organization in some cells. In the course of these studies, we found that the distribution of the myc-epitope and green fluorescence differed in fixed cells, e.g., while the green fluorescence of a myc- and GFP-tagged head domain polypeptide was usually exclusively nuclear, a substantial fraction of the myc-immunoreactivity was cytoplasmic. Treating cells with the translation inhibitor cycloheximide reduces the cytoplasmic myc-signal, suggesting that it represented nascent polypeptides awaiting folding and nuclear import. Based on these types of experiments, GFP can be seen as a marker of the distribution of the mature form of the tagged polypeptide.
Klymkowsky MW
Microscopy research and technique
1999-04-01 00:00
45
1
43-54
Animals,Cell Nucleus,Cells, Cultured,Cytoplasm,Desmosomes,Genes, myc,Green Fluorescent Proteins,Immunohistochemistry,Luminescent Proteins,Plakophilins,Plasmids,Proteins,Xenopus,Luminescent Proteins,Plakophilins,Proteins,Green Fluorescent Proteins
Molecular, Cellular and Developmental Biology, University of Colorado, Boulder 80309-0347, USA klymspotcoloradoedu
Microsc. Res. Tech.
NIGMS GM54001
1059-910X
10.1002/(SICI)1097-0029(19990401)45:1<43::AID-JEMT4>3.0.CO;2-C
10.1002/(SICI)1097-0029(19990401)45:1<43::AID-JEMT4>3.0.CO;2-C
631
True
10206153
