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.
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