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Seven kinds of intermediate filament networks in the cytoplasm of polarized cells: structure and function.

Iwatsuki H, Suda M - Acta Histochem Cytochem (2010)

Bottom Line: However, little information exists on the structure of the IF networks performing these functions.We have clarified the existence of seven kinds of IF networks in the cytoplasm of diverse polarized cells: an apex network just under the terminal web, a peripheral network lying just beneath the cell membrane, a granule-associated network surrounding a mass of secretory granules, a Golgi-associated network surrounding the Golgi apparatus, a radial network locating from the perinuclear region to the specific area of the cell membrane, a juxtanuclear network surrounding the nucleus, and an entire cytoplasmic network.In this review, we describe these seven kinds of IF networks and discuss their biological roles.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Kawasaki Medical School, Matsushima 577, Kurashiki 701-0192, Japan. iwatsuki@med.kawasaki-m.ac.jp

ABSTRACT
Intermediate filaments (IFs) are involved in many important physiological functions, such as the distribution of organelles, signal transduction, cell polarity and gene regulation. However, little information exists on the structure of the IF networks performing these functions. We have clarified the existence of seven kinds of IF networks in the cytoplasm of diverse polarized cells: an apex network just under the terminal web, a peripheral network lying just beneath the cell membrane, a granule-associated network surrounding a mass of secretory granules, a Golgi-associated network surrounding the Golgi apparatus, a radial network locating from the perinuclear region to the specific area of the cell membrane, a juxtanuclear network surrounding the nucleus, and an entire cytoplasmic network. In this review, we describe these seven kinds of IF networks and discuss their biological roles.

No MeSH data available.


Structural model of IF protein. The central α-helical rod domain is subdivided into the coil segments 1A, 1B, 2A and 2B by the short non-helical linker regions L1, L12 and L2. The rod domain is flanked by the non-helical N-terminal head domain and the C-terminal tail domain.
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Figure 2: Structural model of IF protein. The central α-helical rod domain is subdivided into the coil segments 1A, 1B, 2A and 2B by the short non-helical linker regions L1, L12 and L2. The rod domain is flanked by the non-helical N-terminal head domain and the C-terminal tail domain.

Mentions: As shown in Figure 2, all of the IF proteins have a common tripartite structure consisting of a central α-helical rod domain and non-helical N-terminal head and C-terminal tail domains. The size and sequence of the rod domain of the different IF proteins are similar, except for lamins. The lamin rod domain is slightly longer. In contrast, the head and tail domains are highly variable. The rod domains interact with each other to form the core of the filament, whereas the head and tail domains interact with various cytoplasmic elements including other cytoskeletal components [10, 55, 99]. In addition, the head and tail domains play a crucial role in IF assembly, and the organization of IFs is controlled by phosphorylation and dephosphorylation of serine residues in the head and tail domains [53, 92]. The C-terminal tail domain of lamins contains a nuclear localization signal. Therefore, only lamins can form the IF network in the nucleus [52, 88].


Seven kinds of intermediate filament networks in the cytoplasm of polarized cells: structure and function.

Iwatsuki H, Suda M - Acta Histochem Cytochem (2010)

Structural model of IF protein. The central α-helical rod domain is subdivided into the coil segments 1A, 1B, 2A and 2B by the short non-helical linker regions L1, L12 and L2. The rod domain is flanked by the non-helical N-terminal head domain and the C-terminal tail domain.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2875862&req=5

Figure 2: Structural model of IF protein. The central α-helical rod domain is subdivided into the coil segments 1A, 1B, 2A and 2B by the short non-helical linker regions L1, L12 and L2. The rod domain is flanked by the non-helical N-terminal head domain and the C-terminal tail domain.
Mentions: As shown in Figure 2, all of the IF proteins have a common tripartite structure consisting of a central α-helical rod domain and non-helical N-terminal head and C-terminal tail domains. The size and sequence of the rod domain of the different IF proteins are similar, except for lamins. The lamin rod domain is slightly longer. In contrast, the head and tail domains are highly variable. The rod domains interact with each other to form the core of the filament, whereas the head and tail domains interact with various cytoplasmic elements including other cytoskeletal components [10, 55, 99]. In addition, the head and tail domains play a crucial role in IF assembly, and the organization of IFs is controlled by phosphorylation and dephosphorylation of serine residues in the head and tail domains [53, 92]. The C-terminal tail domain of lamins contains a nuclear localization signal. Therefore, only lamins can form the IF network in the nucleus [52, 88].

Bottom Line: However, little information exists on the structure of the IF networks performing these functions.We have clarified the existence of seven kinds of IF networks in the cytoplasm of diverse polarized cells: an apex network just under the terminal web, a peripheral network lying just beneath the cell membrane, a granule-associated network surrounding a mass of secretory granules, a Golgi-associated network surrounding the Golgi apparatus, a radial network locating from the perinuclear region to the specific area of the cell membrane, a juxtanuclear network surrounding the nucleus, and an entire cytoplasmic network.In this review, we describe these seven kinds of IF networks and discuss their biological roles.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Kawasaki Medical School, Matsushima 577, Kurashiki 701-0192, Japan. iwatsuki@med.kawasaki-m.ac.jp

ABSTRACT
Intermediate filaments (IFs) are involved in many important physiological functions, such as the distribution of organelles, signal transduction, cell polarity and gene regulation. However, little information exists on the structure of the IF networks performing these functions. We have clarified the existence of seven kinds of IF networks in the cytoplasm of diverse polarized cells: an apex network just under the terminal web, a peripheral network lying just beneath the cell membrane, a granule-associated network surrounding a mass of secretory granules, a Golgi-associated network surrounding the Golgi apparatus, a radial network locating from the perinuclear region to the specific area of the cell membrane, a juxtanuclear network surrounding the nucleus, and an entire cytoplasmic network. In this review, we describe these seven kinds of IF networks and discuss their biological roles.

No MeSH data available.