Retrovirus-mediated transgenic keratin expression in cultured fibroblasts: specific domain functions in keratin stabilization and filament formation.
With retrovirus-mediated gene transfer, we used intact and deleted keratin proteins to investigate the molecular basis of intermediate filament function. Three levels of assembly show a different stringency for the involvement of individual keratin domains: protein accumulation requires the alpha helix domains; stable filament formation additionally requires both N- and C-terminal domains of either one of the two interacting keratins, suggesting that head to tail homotypic interaction is important for effective elongation; and higher order organization of the cytoplasmic network depends on correct type I-type II pairing of keratins. The presence of two distinct interaction sites along potentially different axes may explain the characteristic morphology of keratin intermediate filament networks.
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Cell Structure Laboratory, Imperial Council Research Fund Clare Hall Labs, Potter's Bar, Hertfordshire, England.
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D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D003599:Cytoskeleton / Q000648:ultrastructure*; D005347:Fibroblasts; D005455:Fluorescent Antibody Technique; D005822:Genetic Vectors; D007382:Intermediate Filaments / Q000502:physiology / Q000648:ultrastructure*; D007633:Keratins / Q000235:genetics / Q000502:physiology*; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011108:Polymers; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship
D046911:Macromolecular Substances; D011108:Polymers; D012333:RNA, Messenger; D011994:Recombinant Proteins; D007633:Keratins