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Colchicine-sensitive and colchicine-insensitive intermediate filament systems distinguished by a new intermediate

H Y Yang1, N Lieska, A E Goldman

  • 1Department of Anatomy and Cell Biology, College of Medicine, University of Illinois, Chicago 60612.

Cell Motility and the Cytoskeleton
|January 1, 1992
PubMed

Insights

Researchers identified novel intermediate filament-associated proteins (IFAP-70/280 kD) that regulate intermediate filament organization. These proteins co-localize with intermediate filaments (IF) and desmin/vimentin, revealing insights into cellular structure.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Intermediate filaments (IF) are crucial cytoskeletal components involved in cellular structure and mechanical stability.
  • The supramolecular organization and regulation of IF assembly and disassembly are not fully understood.
  • Identifying associated proteins is key to elucidating the regulatory mechanisms of IF.

Purpose of the Study:

  • To produce and characterize a monoclonal antibody against intermediate filament-associated proteins (IFAPs) in BHK-21 cells.
  • To investigate the role of newly identified IFAP-70/280 kD in the organization and dynamics of intermediate filaments.
  • To explore the relationship between IFAP-70/280 kD, desmin/vimentin, and colchicine-sensitive/insensitive IF networks.

Main Methods:

  • Production of a monoclonal antibody using a BHK-21 cytoskeletal preparation enriched in IF.
  • Immunoblot analysis, co-isolation, immunofluorescence, and immunoelectron microscopy to characterize IFAP-70/280 kD.
  • In vitro disassembly/assembly assays and double-label immunofluorescence with colchicine treatment.

Main Results:

  • A monoclonal antibody specifically recognized a set of polypeptides designated IFAP-70/280 kD.
  • IFAP-70/280 kD co-isolated, co-localized with IF, and segregated with desmin/vimentin during disassembly/assembly.
  • IFAP-70/280 kD localized to IF regions, suggesting a role in IF supramolecular organization, and differentiated colchicine-sensitive/insensitive IF networks.

Conclusions:

  • IFAP-70/280 kD are integral components of the intermediate filament network in BHK-21 cells.
  • These proteins play a significant role in regulating the organization and potentially the dynamics of intermediate filaments.
  • The study highlights distinct populations of intermediate filaments, including colchicine-insensitive networks potentially associated with actin stress fibers.

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