Dynamic aspects of intermediate filament networks in BHK-21 cells.
A procedure was developed for the conjugation of vimentin with biotin. Biotinylated vimentin was then microinjected into BHK-21 cells and the fate of the labeled protein was determined at various times postinjection by indirect immunofluorescence. Microinjected vimentin could be traced through a specific sequence of morphological changes ultimately resulting in the formation of a filamentous network. The injected protein was first detected in spots dispersed throughout the cytoplasm. Subsequently, these spots appeared to cluster near the nucleus where they merged into a diffuse "cap." This cap coincided with a concentration of endogenous intermediate filaments and eventually gave rise to a filamentous network that was coincident with the endogenous intermediate filament network as determined by double-label immunofluorescence. The results indicate that the incorporation of exogenous vimentin into a filamentous network is initiated in a perinuclear region and progresses in a polarized fashion toward the cell surface.
Vikstrom
K L
KL
Department of Cell Biology and Anatomy, Northwestern University Medical School, Chicago, IL 60611.
Borisy
G G
GG
Goldman
R D
RD
D000818:Animals; D001710:Biotin; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D007382:Intermediate Filaments / Q000378:metabolism*; D008845:Microinjections; D014746:Vimentin / Q000378:metabolism*
D014746:Vimentin; D001710:Biotin