Intermediate filaments (IFs) are cytoskeletal structural components found in the cells of vertebrates, and many invertebrates. Homologues of the IF protein have been noted in an invertebrate, the cephalochordate Branchiostoma.
Desmin is a protein that in humans is encoded by the DES gene. Desmin is a muscle-specific, type III intermediate filament that integrates the sarcolemma, Z disk, and nuclear membrane in sarcomeres and regulates sarcomere architecture.
Vimentin is a structural protein that in humans is encoded by the VIM gene. Its name comes from the Latin vimentum which refers to an array of flexible rods.
Peripherin is a type III intermediate filament protein expressed mainly in neurons of the peripheral nervous system. It is also found in neurons of the central nervous system that have projections toward peripheral structures, such as spinal motor neurons. Its size, structure, and sequence/location of protein motifs is similar to other type III intermediate filament proteins such as desmin, vimentin and glial fibrillary acidic protein. Like these proteins, peripherin can self-assemble to form homopolymeric filamentous networks, but it can also heteropolymerize with neurofilaments in several neuronal types. This protein in humans is encoded by the PRPH gene. Peripherin is thought to play a role in neurite elongation during development and axonal regeneration after injury, but its exact function is unknown. It is also associated with some of the major neuropathologies that characterize amyotropic lateral sclerosis (ALS), but despite extensive research into how neurofilaments and peripherin contribute to ALS, their role in this disease is still unidentified.
Plectin is a giant protein found in nearly all mammalian cells which acts as a link between the three main components of the cytoskeleton: actin microfilaments, microtubules and intermediate filaments. In addition, plectin links the cytoskeleton to junctions found in the plasma membrane that structurally connect different cells. By holding these different networks together, plectin plays an important role in maintaining the mechanical integrity and viscoelastic properties of tissues.
Nestin is a protein that in humans is encoded by the NES gene.
Keratin, type II cytoskeletal 8 also known as cytokeratin-8 (CK-8) or keratin-8 (K8) is a keratin protein that is encoded in humans by the KRT8 gene. It is often paired with keratin 18.
Synemin, also known as desmuslin, is a protein that in humans is encoded by the SYNM gene. Synemin is an intermediate filament (IF) family member. IF proteins are cytoskeletal proteins that confer resistance to mechanical stress and are encoded by a dispersed multigene family. This protein has been found to form a linkage between desmin, which is a subunit of the IF network, and the extracellular matrix, and provides an important structural support in muscle.
Gamma-crystallin D is a protein that in humans is encoded by the CRYGD gene.
Lens fiber major intrinsic protein also known as aquaporin-0 is a protein that in humans is encoded by the MIP gene.
Crystallin, gamma C, also known as CRYGC, is a protein which in humans is encoded by the CRYGC gene.
Periplakin is a protein that in humans is encoded by the PPL gene.
Transcription factor Maf, also known as proto-oncogene c-Maf or V-maf musculoaponeurotic fibrosarcoma oncogene homolog, is a transcription factor that in humans is encoded by the MAF gene.
Beta-crystallin B1 is a protein that in humans is encoded by the CRYBB1 gene. Variants in CRYBB1 are associated with autosomal dominant congenital cataract.
Beta-crystallin A3 is a protein that in humans is encoded by the CRYBA1 gene.
BFSP2 is a gene that encodes the protein phakinin in humans.
Gamma-crystallin A is a protein that in humans is encoded by the CRYGA gene.
Lens fiber membrane intrinsic protein is a protein that in humans is encoded by the LIM2 gene.
SOX1 is a gene that encodes a transcription factor with a HMG-box DNA-binding domain and functions primarily in neurogenesis. SOX1, SOX2 and SOX3, members of the SOX gene family, contain transcription factors related to SRY, the testis-determining factor.
Intermediate filament family orphan 1 is a protein that in humans is encoded by the IFFO1 gene. IFFO1 has uncharacterized function and a weight of 61.98 kDa. IFFO1 proteins play an important role in the cytoskeleton and the nuclear envelope of most eukaryotic cell types.
