Table 1.
Intermediate filament types, characteristic cell subsets and main function
| IF type | Protein | No genes | Size (kDa) | Cell subsets | Function | References |
|---|---|---|---|---|---|---|
| I | Keratins (acidic) | > 25 | 40–60 | K9–K20 and K23: soft epithelia; K31–K38: hard epithelia | Structural integrity, mechanical resistance, adhesion, signal transduction, inflammation, proliferation, apoptosis, motility | [116–119] |
| II | Keratins (basic) | > 24 | 50–70 | K1–K8: soft epithelia; K81–K86, hard epithelia; K71–K74: inner root sheath | ||
| III | Vimentin | 1 | 53 | Mesenchymal cells, developing neurons, astrocytes, endothelial cells, leukocytes | Structural maintenance, cell shape, motility, focal adhesion | [74] |
| Glial fibrillary acidic protein | 1 | 51 | Neural stem cells, radial glia-like precursors, astrocytes, regenerative glia, mature glia in CNS and PNS | Structural maintenance, cell shape, motility | [2, 71–74, 120] | |
| Desmin | 1 | 53 | Satellite stem cells, striated muscle, replicating myoblasts, fibroblastic reticular cells of lymphoid organs | Contraction | [121, 122] | |
| Peripherin | 1 | 58 | Mature neurons in PNS | Neurite elongation | [123] | |
| Syncoilin | 1 | 64 | Skeletal and cardiac muscle, nervous system | Structural maintenance | [124] | |
| IV | NF light | 1 | 68 | Maturing neurons in CNS, mature neurons in PNS and CNS | Functional maintenance, intracellular transport, morphogenesis of neurons | [125] |
| NF medium | 1 | 160 | ||||
| NF heavy | 1 | 240 | ||||
| α-Internexin | 1 | 66 | Postnatal, maturing and mature neurons | [126] | ||
| Synemin | 1 | 230 | Mature neurons in PNS, glia, skeletal and cardiac muscle | Structural maintenance | [74] | |
| V | Lamin A/C | 1 | 60–75 | Nucleus, cell specific | Nuclear shape, chromatin scaffold, gene expression, differentiation, migration | [42, 127, 128] |
| Lamin B1 | 1 | |||||
| Lamin B2 | 1 | |||||
| VI | Nestin | 1 | 240 | Neural stem and progenitor cells, neurogenic cells, radial glia-like precursors, regenerative glia, mesenchymal stromal cells, subsets of endothelial cells, Schwann cell precursors in PNS | Self-renewal, proliferation, survival, differentiation, migration | [2, 9, 10, 20, 36, 47, 48, 50] |
K keratin, CNS central nervous system, PNS peripheral nervous system, NF neurofilament