Rodzaje filamentów pośrednich

Intermediate filaments are of six types. The first four contribute to cytoplasmic architecture. Type five is found abundantly within the inner lining of the nuclear membrane, while the recently discovered type six is predominantly found in lens cells and neuronal stem cells.

Types one and two consist of interdependent keratin proteins and form heterodimeric filaments found primarily in epithelial cells. Both have high tensile strength, and are commonly found in tissues undergoing repeated wear and tear, such as nails and skin.

Type three consists of four proteins—vimentin, desmin, glial fibrillary acidic protein, and peripherin. They can form both homo and heterodimers.

Type four includes neurofilament or NF proteins, with glutamic acid-rich tails, and filaments with short sidearms, that provide axon structural support and determine axon diameter.

Type five consists of nuclear lamins having an immunoglobulin-fold with a CAAX box consisting of cysteine, two aliphatic amino acids, and another non-specific amino acid at its C-terminal.

Lastly, type six consists of beaded intermediate filaments that can either form homo or heterodimers with each other.