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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.


Schematic illustration showing the localization of the seven kinds of IF networks in the cytoplasm of a polarized cell. Red lines indicate IF networks. An apex network (nw.) exists under the apical cell membrane. A peripheral network is distributed just beneath the basolateral cell membrane. A granule-associated network surrounds a mass of secretory granules. A Golgi-associated network surrounds the Golgi apparatus. A radial network (R) is located from the perinuclear region to the specific area of the cell membrane. A juxtanuclear network (J) surrounds the nucleus. An entire cytoplasmic network is distributed throughout the entire cytoplasm.
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Figure 1: Schematic illustration showing the localization of the seven kinds of IF networks in the cytoplasm of a polarized cell. Red lines indicate IF networks. An apex network (nw.) exists under the apical cell membrane. A peripheral network is distributed just beneath the basolateral cell membrane. A granule-associated network surrounds a mass of secretory granules. A Golgi-associated network surrounds the Golgi apparatus. A radial network (R) is located from the perinuclear region to the specific area of the cell membrane. A juxtanuclear network (J) surrounds the nucleus. An entire cytoplasmic network is distributed throughout the entire cytoplasm.

Mentions: IFs are the most stable components in the cells under physiological conditions. When cells are treated with concentrated salt solution and nonionic detergents, the IF networks are retained in their normal arrangement, whereas the vast majority of cytoplasmic and nuclear constituents are lost [71]. Moreover, IFs have a long half-life, roughly equivalent to the cell generation time, whereas the half-life of IF protein mRNA is very short. For instance, the half-life of vimentin mRNA in mouse fibroblasts is about 6 hr [22]. Therefore, for a long time it was thought that the IF network had a fixed architecture that protects cells against various forms of mechanical stress. However, since IFs are highly dynamic and reorganize by phosphorylation, glycosylation, and transglutamination [56, 92, 107], recent studies suggest that the IF network is involved in many important physiological functions, such as the distribution of organelles [16, 46, 99], signal transduction [56], cell polarity [108], and gene regulation [21, 24, 112]. On the other hand, little information exists concerning the structure of the IF networks performing these functions. We have examined the relation between cell differentiation and expression of IF protein in the polarized cells of the digestive, respiratory, nervous, and endocrine systems, as well as the eye, in a series of research studies [58–66, 105]. In these studies, we have clarified the existence of the following seven kinds of IF networks in the cytoplasm of polarized cells: an apex network, a peripheral network, a granule-associated network, a Golgi-associated network, a radial network, a juxtanuclear network, and an entire cytoplasmic network (Fig. 1). This article examines recent studies of IFs and discusses the functions of these seven kinds of IF networks.


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

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

Schematic illustration showing the localization of the seven kinds of IF networks in the cytoplasm of a polarized cell. Red lines indicate IF networks. An apex network (nw.) exists under the apical cell membrane. A peripheral network is distributed just beneath the basolateral cell membrane. A granule-associated network surrounds a mass of secretory granules. A Golgi-associated network surrounds the Golgi apparatus. A radial network (R) is located from the perinuclear region to the specific area of the cell membrane. A juxtanuclear network (J) surrounds the nucleus. An entire cytoplasmic network is distributed throughout the entire cytoplasm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 1: Schematic illustration showing the localization of the seven kinds of IF networks in the cytoplasm of a polarized cell. Red lines indicate IF networks. An apex network (nw.) exists under the apical cell membrane. A peripheral network is distributed just beneath the basolateral cell membrane. A granule-associated network surrounds a mass of secretory granules. A Golgi-associated network surrounds the Golgi apparatus. A radial network (R) is located from the perinuclear region to the specific area of the cell membrane. A juxtanuclear network (J) surrounds the nucleus. An entire cytoplasmic network is distributed throughout the entire cytoplasm.
Mentions: IFs are the most stable components in the cells under physiological conditions. When cells are treated with concentrated salt solution and nonionic detergents, the IF networks are retained in their normal arrangement, whereas the vast majority of cytoplasmic and nuclear constituents are lost [71]. Moreover, IFs have a long half-life, roughly equivalent to the cell generation time, whereas the half-life of IF protein mRNA is very short. For instance, the half-life of vimentin mRNA in mouse fibroblasts is about 6 hr [22]. Therefore, for a long time it was thought that the IF network had a fixed architecture that protects cells against various forms of mechanical stress. However, since IFs are highly dynamic and reorganize by phosphorylation, glycosylation, and transglutamination [56, 92, 107], recent studies suggest that the IF network is involved in many important physiological functions, such as the distribution of organelles [16, 46, 99], signal transduction [56], cell polarity [108], and gene regulation [21, 24, 112]. On the other hand, little information exists concerning the structure of the IF networks performing these functions. We have examined the relation between cell differentiation and expression of IF protein in the polarized cells of the digestive, respiratory, nervous, and endocrine systems, as well as the eye, in a series of research studies [58–66, 105]. In these studies, we have clarified the existence of the following seven kinds of IF networks in the cytoplasm of polarized cells: an apex network, a peripheral network, a granule-associated network, a Golgi-associated network, a radial network, a juxtanuclear network, and an entire cytoplasmic network (Fig. 1). This article examines recent studies of IFs and discusses the functions of these seven kinds of IF networks.

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.