Intermediate Filaments by Lina Wu: Difference between revisions
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There is a wide range of IFs with different chemical and physical properties that allow them to take on specialized functions in different types of cells or different regions of the cells. The most prevalent and obvious function of IFs is mechanical support. Unlike plants and fungi that have a rigid cell walls, animal cells must rely on the cytoskeleton to support the cell and the surrounding tissues [laz]. IFs are have a relatively larger role than actin or microtubules because the rope-like fibers are very strong and are not easily depolymerized like the other fibers [lodi]. In epithelial cells, keratin IFs form a strong network that links cells to each other through desmosomes and to the extracellular matrix or basal membrane through hemidesmosomes [coul]. The rigid nature of IFs also serves to maintain cytoarchitecture of certain cells. IFs in motor neurons control the axon radius while nuclear lamins maintain the shape and structure of cell nuclei [coul, turgay]. Post-translational modification of IFs have been shown to control fiber solubility and depolymerization, which is used to alter the viscoelastic properties of the cell as it moves [snider]. More recently, the interconnectedness of the IF network throughout the cell, nucleus, and surrounding cells or ECM has been shown to play a large role in signal transduction. IFs that connect to the cellular membrane or to other filaments like microtubules can transmit signals to the nucleus where different IFs can actually sort and activate certain genes [??]. | There is a wide range of IFs with different chemical and physical properties that allow them to take on specialized functions in different types of cells or different regions of the cells. The most prevalent and obvious function of IFs is mechanical support. Unlike plants and fungi that have a rigid cell walls, animal cells must rely on the cytoskeleton to support the cell and the surrounding tissues [laz]. IFs are have a relatively larger role than actin or microtubules because the rope-like fibers are very strong and are not easily depolymerized like the other fibers [lodi]. In epithelial cells, keratin IFs form a strong network that links cells to each other through desmosomes and to the extracellular matrix or basal membrane through hemidesmosomes [coul]. The rigid nature of IFs also serves to maintain cytoarchitecture of certain cells. IFs in motor neurons control the axon radius while nuclear lamins maintain the shape and structure of cell nuclei [coul, turgay]. Post-translational modification of IFs have been shown to control fiber solubility and depolymerization, which is used to alter the viscoelastic properties of the cell as it moves [snider]. More recently, the interconnectedness of the IF network throughout the cell, nucleus, and surrounding cells or ECM has been shown to play a large role in signal transduction. IFs that connect to the cellular membrane or to other filaments like microtubules can transmit signals to the nucleus where different IFs can actually sort and activate certain genes [??]. | ||
[[ | [[Image:IF_functions.jpg|thumb|General functions for various IFs found throughout the body]] | ||
Revision as of 00:58, 23 March 2017
Intermediate Filaments
Background
Intermediate filaments (IF) are a superfamily of fibers of diameter ~10nm that are found predominantly in eukaryotic cells of multicellular organisms [Fuchs]. IFs are one of three major components that make up the cytoskeleton of the cell. They have a diameter between those of thinner actin microfilaments and thicker microtubules, which are the other major components of the cytoskeleton [Laz]. IFs differ from actin and microtubules in that they are made up of numerous different subunits that copolymerize to form a variety of IFs with different properties and functions [fuchs].
Functions
There is a wide range of IFs with different chemical and physical properties that allow them to take on specialized functions in different types of cells or different regions of the cells. The most prevalent and obvious function of IFs is mechanical support. Unlike plants and fungi that have a rigid cell walls, animal cells must rely on the cytoskeleton to support the cell and the surrounding tissues [laz]. IFs are have a relatively larger role than actin or microtubules because the rope-like fibers are very strong and are not easily depolymerized like the other fibers [lodi]. In epithelial cells, keratin IFs form a strong network that links cells to each other through desmosomes and to the extracellular matrix or basal membrane through hemidesmosomes [coul]. The rigid nature of IFs also serves to maintain cytoarchitecture of certain cells. IFs in motor neurons control the axon radius while nuclear lamins maintain the shape and structure of cell nuclei [coul, turgay]. Post-translational modification of IFs have been shown to control fiber solubility and depolymerization, which is used to alter the viscoelastic properties of the cell as it moves [snider]. More recently, the interconnectedness of the IF network throughout the cell, nucleus, and surrounding cells or ECM has been shown to play a large role in signal transduction. IFs that connect to the cellular membrane or to other filaments like microtubules can transmit signals to the nucleus where different IFs can actually sort and activate certain genes [??].
