In:
Journal of Cell Science, The Company of Biologists, Vol. 110, No. 2 ( 1997-01-15), p. 169-178
Abstract:
The high molecular mass protein, HD1, is a structural protein present in hemidesmosomes as well as in distinct adhesion structures termed type II hemidesmosomes. We have studied the distribution and expression of HD1 in the GD25 cells, derived from murine embryonal stem cells deficient for the β1 integrin subunit. We report here that these cells possess HD1 but not BP230 or BP180, two other hemidesmosomal constituents, and express only traces of the α6β4 integrin. By immunofluorescence and interference reflection microscopy HD1 was found together with vinculin at the end of actin filaments in focal contacts. In OVCAR-4 cells, derived from a human ovarian carcinoma which, like GD25 cells, only weakly express α6β4, HD1 was also localized in focal contacts. Upon transfection of both GD25 and OVCAR-4 cells with cDNA for the human β4 subunit the subcellular distribution of HD1 changed significantly. HD1 is then no longer present in focal contacts but in other structures at cell-substrate contacts, colocalized with α6β4. These junctional complexes are probably the equivalent of the type II hemidesmosomes. Transfection of GD25 cells with β1 cDNA did not affect the distribution of HD1, which indicates that the localization of HD1 in focal contacts was not due to the absence of β1. Moreover, in GD25 cells transfected with cDNA encoding a β4/β1 chimera, in which the cytoplasmic domain of β4 was replaced by that of β1, the distribution of HD1 was unaffected. Our findings indicate that the cytoplasmic domain of β4 determines the subcellular distribution of HD1 and emphasize the important role of α6β4 in the assembly of hemidesmosomes and other junctional adhesive complexes containing HD1.
Type of Medium:
Online Resource
ISSN:
0021-9533
,
1477-9137
DOI:
10.1242/jcs.110.2.169
Language:
English
Publisher:
The Company of Biologists
Publication Date:
1997
detail.hit.zdb_id:
219171-4
detail.hit.zdb_id:
1483099-1
SSG:
12
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