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Cytoskeleton

Microtubulus:

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Dynamic instability of microtubules

Vesicle and organelle transport

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Axonemal microtubules

Microtubuls responsible for mitosis

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Intermediet filament :The assembly of IF

Intermediate filament proteins with particular biological, histological, or pathological

importance include the following:

Keratins(Gr. keras, horn) or cytokeratins are a diverse family of acidic and basic isoforms that

compose heterodimer subunits of intermediate filaments in all epithelial cell. They are encoded

by over 30 related genes and produce filaments with different chemical and immunologic

properties for various functions. In epidermal cells, cytokeratins accumulatein the

differentiation process termed keratinization, which results in an outer layer of nonliving skin

cells that reduces dehydration. The evolution of keratins made terrestrial life possible.

Keratinization also provides some protection from minor abrasions and produces various hard

protective structures of skin, such as nails (as well as feathers, beaks, horns, and the scales of

reptiles). Intermediate filaments of keratins form large bundles (tonofibrils) that attach to

certain junctions between epithelial cells.

Vimentinisthe most common class III intermediate filament protein and is found in most cells

derived from mesenchyme. Important vimentin-like proteins include desminfound in almost all

muscle cells and glial fibrillar acidic protein (GFAP) found especially in astrocytes, supportingcells of central nervous system tissue.

Neurofilamentproteinsof three distinct sizes make heterodimers that form the subunits of

the major intermediate filaments of neurons.

Laminsarea family of seven isoforms present in the cell nucleus, where they form a structural

framework called the nuclear lamina just inside the nuclear envelope

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Microfilament :Actin polymerization

Concentration og G-Actin and treadmilling of actin filament

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Actin in sarcomer

Actin in cytokinesis Actin in microvilli

Actin in cell motility

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Spectrin membrane skeleton