Intermediate filament assembly and stability in vitro: effect and implications of the removal of head and tail domains of vimentin by the human immunodeficiency virus type 1 protease.
The intermediate filament subunit protein vimentin is efficiently cleaved in vitro by purified human immunodeficiency virus type 1 protease. Immunological data confirm that identical sites are cleaved when vimentin is polymerized into filaments or occurs as protofilaments. The primary cleavage gives rise to a molecule lacking most of the tail domain and which not only remains in preformed filaments, but is also capable of polymerizing into essentially normal 10 nm filaments. However, these filaments show a propensity to form large lateral aggregates. The three secondary cleavage products of vimentin additionally lack portions of the head domain, are almost quantitatively (greater than 95%) released from preformed filaments and are not capable of forming filaments de novo. These results extend the limits of the head and tail domains of vimentin that play a role in filament formation and stability.
Max-Planck-Institut für Zellbiologie, Landenburg/Heidelberg, Federal Republic of Germany.
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RL
Shoeman
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Mothes
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C
Kesselmeier
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Traub
D000818:Animals; D003599:Cytoskeleton / Q000187:drug effects*; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism / Q000502:physiology; D015684:Gene Products, pol / Q000378:metabolism / Q000502:physiology; D016333:HIV Protease; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007382:Intermediate Filaments / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008854:Microscopy, Electron; D014746:Vimentin / Q000378:metabolism* / Q000502:physiology
D015684:Gene Products, pol; D014746:Vimentin; D010450:Endopeptidases; D016333:HIV Protease