A vimentin monomer, like all other intermediate filaments, has a central α-helical domain, capped on each end by non-helical amino (head) and carboxyl (tail) domains. Two monomers are likely co-translationally expressed in a way that facilitates their formation of a coiled-coil dimer, which is the basic subunit of vimentin assembly.
The α-helical sequences contain a pattern of hydrophobic amino acids that contribute to forming a "hydrophobic seal" on the surface of the helix. In addition, there is a periodic distribution of acidic and basic amino acids that seems to play an important role in stabilizing coiled-coil dimers. The spacing of the charged residues is optimal for ionic salt bridges, which allows for the stabilization of the α-helix structure. While this type of stabilization is intuitive for intrachain interactions, rather than interchain interactions, scientists have proposed that perhaps the switch from intrachain salt bridges formed by acidic and basic residues to the interchain ionic associations contributes to the assembly of the filament.
The dynamic nature of vimentin is important when offering flexibility to the cell. Scientists found that vimentin provided cells with a resilience absent from the microtubule or actin filament networks, when under mechanical stress in vivo. Therefore, in general, it is accepted that vimentin is the cytoskeletal component responsible for maintaining cell integrity. (It was found that cells without vimentin are extremely delicate when disturbed with a micropuncture).Transgenic mice that lack vimentin appeared normal and did not show functional differences. It is possible that the microtubule network may have compensated for the absence of the intermediate network. This result supports an intimate interactions between microtubules and vimentin. Moreover, when microtubule depolymerizers were present, vimentin reorganization occurred, once again implying a relationship between the two systems. On the other hand, wounded mice that lack the vimentin gene heal slower than their wild type counterparts.
In essence, vimentin is responsible for maintaining cell shape, integrity of the cytoplasm, and stabilizing cytoskeletal interactions. Vimentin has been shown to eliminate toxic proteins in JUNQ and IPODinclusion bodies in asymmetric division of mammalian cell lines.
Also, vimentin is found to control the transport of low-density lipoprotein, LDL, -derived cholesterol from a lysosome to the site of esterification. With the blocking of transport of LDL-derived cholesterol inside the cell, cells were found to store a much lower percentage of the lipoprotein than normal cells with vimentin. This dependence seems to be the first process of a biochemical function in any cell that depends on a cellular intermediate filament network. This type of dependence has ramifications on the adrenal cells, which rely on cholesteryl esters derived from LDL.
Vimentin plays a role in aggresome formation, where it forms a cage surrounding a core of aggregated protein.
Methylation of the vimentin gene has been established as a biomarker of colon cancer and this is being utilized in the development of fecal tests for colon cancer. Statistically significant levels of vimentin gene methylation have also been observed in certain upper gastrointestinal pathologies such as Barrett's esophagus, esophageal adenocarcinoma, and intestinal type gastric cancer. High levels of DNA methylation in the promotor region have also been associated with markedly decreased survival in hormone positive breast cancers. Downregulation of vimentin was identified in cystic variant of papillary thyroid carcinoma using a proteomic approach. See also Anti-citrullinated protein antibody for its use in diagnosis of rheumatoid arthritis.
^Katsumoto T.; Mitsushima A.; Kurimura T. (1990). "The role of the vimentin intermediate filaments in rat 3Y1 cells elucidated by immunoelectron microscopy and computer-graphic reconstruction". Biol Cell68 (2): 139–46. doi:10.1016/0248-4900(90)90299-I. PMID2192768.
^Golucci-Guyon E, Portier MM, Dunia I, Paulin D, Pournin S, Babinet C (1994). "Mice lacking vimentin develop and reproduce without an obvious phenotype.". Cell79 (4): 679–94. doi:10.1016/0092-8674(94)90553-3. PMID7954832.
^Eckes B, Colucci-Guyon E, Smola H, Nodder S, Babinet C, Krieg T, Martin P (2000). "Impaired wound healing in embryonic and adult mice lacking vimentin.". Journal of Cell Science113: 2455–62. PMID10852824.
^ abSarria AJ, Panini SR, Evans RM (September 1992). "A functional role for vimentin intermediate filaments in the metabolism of lipoprotein-derived cholesterol in human SW-13 cells". J. Biol. Chem.267 (27): 19455–63. PMID1527066.
^Dinets A, Pernemalm M, Kjellin H, Sviatoha V, Sofiadis A, Juhlin CC, Zedenius J, Larsson C, Lehtiö J, Höög A (May 2015). "Differential protein expression profiles of cyst fluid from papillary thyroid carcinoma and benign thyroid lesions". PLOS ONE10 (5): e0126472. doi:10.1371/journal.pone.0126472. PMID25978681.
^Meng JJ, Bornslaeger EA, Green KJ, Steinert PM, Ip W (1997). "Two-hybrid analysis reveals fundamental differences in direct interactions between desmoplakin and cell type-specific intermediate filaments". J. Biol. Chem.272 (34): 21495–503. doi:10.1074/jbc.272.34.21495. PMID9261168.
^Lopez-Egido J, Cunningham J, Berg M, Oberg K, Bongcam-Rudloff E, Gobl A (2002). "Menin's interaction with glial fibrillary acidic protein and vimentin suggests a role for the intermediate filament network in regulating menin activity". Exp. Cell Res.278 (2): 175–83. doi:10.1006/excr.2002.5575. PMID12169273.
^Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, Berriz GF, Gibbons FD, Dreze M, Ayivi-Guedehoussou N, Klitgord N, Simon C, Boxem M, Milstein S, Rosenberg J, Goldberg DS, Zhang LV, Wong SL, Franklin G, Li S, Albala JS, Lim J, Fraughton C, Llamosas E, Cevik S, Bex C, Lamesch P, Sikorski RS, Vandenhaute J, Zoghbi HY, Smolyar A, Bosak S, Sequerra R, Doucette-Stamm L, Cusick ME, Hill DE, Roth FP, Vidal M (2005). "Towards a proteome-scale map of the human protein-protein interaction network". Nature437 (7062): 1173–8. doi:10.1038/nature04209. PMID16189514.
^Stelzl U, Worm U, Lalowski M, Haenig C, Brembeck FH, Goehler H, Stroedicke M, Zenkner M, Schoenherr A, Koeppen S, Timm J, Mintzlaff S, Abraham C, Bock N, Kietzmann S, Goedde A, Toksöz E, Droege A, Krobitsch S, Korn B, Birchmeier W, Lehrach H, Wanker EE (2005). "A human protein-protein interaction network: a resource for annotating the proteome". Cell122 (6): 957–68. doi:10.1016/j.cell.2005.08.029. PMID16169070.
^Herrmann H, Wiche G (1987). "Plectin and IFAP-300K are homologous proteins binding to microtubule-associated proteins 1 and 2 and to the 240-kilodalton subunit of spectrin". J. Biol. Chem.262 (3): 1320–5. PMID3027087.
^ abBrown MJ, Hallam JA, Liu Y, Yamada KM, Shaw S (2001). "Cutting edge: integration of human T lymphocyte cytoskeleton by the cytolinker plectin". J. Immunol.167 (2): 641–5. doi:10.4049/jimmunol.167.2.641. PMID11441066.
^Matsuzawa K, Kosako H, Inagaki N, Shibata H, Mukai H, Ono Y, Amano M, Kaibuchi K, Matsuura Y, Azuma I, Inagaki M (1997). "Domain-specific phosphorylation of vimentin and glial fibrillary acidic protein by PKN". Biochem. Biophys. Res. Commun.234 (3): 621–5. doi:10.1006/bbrc.1997.6669. PMID9175763.
^Russell RL, Cao D, Zhang D, Handschumacher RE, Pizzorno G (2001). "Uridine phosphorylase association with vimentin. Intracellular distribution and localization". J. Biol. Chem.276 (16): 13302–7. doi:10.1074/jbc.M008512200. PMID11278417.
^Tzivion G, Luo ZJ, Avruch J (2000). "Calyculin A-induced vimentin phosphorylation sequesters 14-3-3 and displaces other 14-3-3 partners in vivo". J. Biol. Chem.275 (38): 29772–8. doi:10.1074/jbc.M001207200. PMID10887173.