|
( Intermediate filament)
Intermediate filaments (IFs) are cytoskeletal structures formed by members of a family of related proteins. Intermediate filaments have a diameter between that of actin (microfilaments) and microtubules. Most types of intermediate filaments are located in the cytosol between the nuclear envelope and the cell surface membrane. Nuclear lamins are localized to the cell nucleus. The domain structure of IF molecules is conserved. Each protein has a non-alpha-helical (globular) domain at the N and C-termini which surrounds the alpha-helical rod domain. The basic building block for IFs is a parallel and in register dimer. The dimer is formed through the interaction of the rod domain to form a coiled coil. Cytoplasmic IF assemble into non-polar unit-length filaments which then assemble into longer structures. The anti-parallel orientation of tetramers means that, unlike microtubules and microfilaments which have a plus end and a minus end, IFs lack polarity. Cytoplasmic IF do not undergo treadmilling like microtubules and actin fibers, but they are dynamic. For a review see [1].
|
Intermediate filament Subcategories
Intermediate filament Articles
|
| 
