Plectin

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Plectin 1, intermediate filament binding protein 500kDa
PDB rendering based on 1mb8.
Available structures: 1mb8, 1sh5, 1sh6, 2odu, 2odv
Identifiers
Symbol(s) PLEC1; HD1; PCN; EBS1; EBSO; PLEC1b; PLTN
External IDs OMIM: 601282 MGI: 1277961 HomoloGene: 384
Orthologs
Human Mouse
Entrez 5339 18810
Ensembl n/a ENSMUSG00000022565
Uniprot n/a Q6S390
Refseq NM_000445 (mRNA)
NP_000436 (protein)		 XM_994758 (mRNA)
XP_999852 (protein)
Location n/a Chr 15: 76 - 76.06 Mb
Pubmed search [1] [2]

Plectin is a giant protein (c500 kDa) 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.[1] 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.[2]

Contents

[edit] Structure

The structure of plectin is thought to be a dimer consisting of a central coiled coil of alpha helices connected to large globular domains at each terminus. These globular domains are responsible for connecting plectin to its various cytoskeletal targets. The carboxy-terminal domain is made of 6 highly homologous repeating regions. The subdomain between regions five and six of this domain is known to connect to the intermediate filaments cytokeratin and vimentin. At the opposite end of the protein, in the N-terminal domain, a region has been defined as responsible for binding to actin. In 2004 the exact crystal structure of this actin binding domain(ABD) was determined in mice and shown to be composed of two calponin homology(CH) domains.[3]

[edit] Function

Through the use of gold-immunoelectron microscopy, immunoblotting and immunofluorescence experiments plectin has been found to associate with all three major components of the cytoskeleton. With the use of microscopy especially plectin has been shown to directly connect microtubules to intermediate filaments as well as to each other. While plectin has been observed to mediate interactions between actin and intermediate filaments and associate with each independently, a direct linkage by plectin between these two filaments has not been completely proven. It may be that plectin actually connects to proteins associated with each rather than directly. Besides serving as a linker protein between the main elements of the cytoskeleton, plectin also forms connections between other cytoskeletally related proteins as well. Plectin has been shown to directly link Myosin II motor proteins and intermediate filaments. In in vitro assays plectin has been found to bind subplasma membrane skeleton proteins such as alpha-spectrin and fodrin. Over the past decade plectin has been identified as an important component linking the cytoskeleton to intercellular junctions which enable the structural integrity of a tissue as a whole. Two such junctions, Desmosomes and Hemidesmosomes which link intermediate filament networks between cells have been shown to associate with plectin. Plectin has been revealed to localize to the desmosomes and in vitro studies have shown that it can form bridges between the desmosome protein, desmoplakin and intermediate filaments. In hemidesmosomes plectin has been shown to interact with the integrin β4 subunits of the hemidesmosome plaque and function in a clamp like manner to crosslink the intermediate filament, cytokeratin to the junction.

[edit] References

  1. ^ Svitkina TM, Verkhovsky AB, Borisy GG (1996). "Plectin sidearms mediate interaction of intermediate filaments with microtubules and other components of the cytoskeleton". J. Cell Biol. 135 (4): 991–1007. doi:10.1083/jcb.135.4.991. PMID 8922382. 
  2. ^ Wiche G (1998). "Role of plectin in cytoskeleton organization and dynamics" (abstract). J. Cell. Sci. 111 ( Pt 17): 2477–86. PMID 9701547. 
  3. ^ Sevcík J, Urbániková L, Kost'an J, Janda L, Wiche G (2004). "Actin-binding domain of mouse plectin. Crystal structure and binding to vimentin". Eur. J. Biochem. 271 (10): 1873–84. doi:10.1111/j.1432-1033.2004.04095.x. PMID 15128297. 

[edit] Further reading

  • Pfendner E, Rouan F, Uitto J (2005). "Progress in epidermolysis bullosa: the phenotypic spectrum of plectin mutations.". Exp. Dermatol. 14 (4): 241–9. doi:10.1111/j.0906-6705.2005.00324.x. PMID 15810881. 
  • Foisner R, Traub P, Wiche G (1991). "Protein kinase A- and protein kinase C-regulated interaction of plectin with lamin B and vimentin.". Proc. Natl. Acad. Sci. U.S.A. 88 (9): 3812–6. PMID 2023931. 
  • 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. PMID 3027087. 
  • Malecz N, Foisner R, Stadler C, Wiche G (1996). "Identification of plectin as a substrate of p34cdc2 kinase and mapping of a single phosphorylation site.". J. Biol. Chem. 271 (14): 8203–8. PMID 8626512. 
  • Liu CG, Maercker C, Castañon MJ, et al. (1996). "Human plectin: organization of the gene, sequence analysis, and chromosome localization (8q24).". Proc. Natl. Acad. Sci. U.S.A. 93 (9): 4278–83. PMID 8633055. 
  • Gache Y, Chavanas S, Lacour JP, et al. (1996). "Defective expression of plectin/HD1 in epidermolysis bullosa simplex with muscular dystrophy.". J. Clin. Invest. 97 (10): 2289–98. PMID 8636409. 
  • Smith FJ, Eady RA, Leigh IM, et al. (1996). "Plectin deficiency results in muscular dystrophy with epidermolysis bullosa.". Nat. Genet. 13 (4): 450–7. doi:10.1038/ng0896-450. PMID 8696340. 
  • McLean WH, Pulkkinen L, Smith FJ, et al. (1996). "Loss of plectin causes epidermolysis bullosa with muscular dystrophy: cDNA cloning and genomic organization.". Genes Dev. 10 (14): 1724–35. PMID 8698233. 
  • Nikolic B, Mac Nulty E, Mir B, Wiche G (1996). "Basic amino acid residue cluster within nuclear targeting sequence motif is essential for cytoplasmic plectin-vimentin network junctions.". J. Cell Biol. 134 (6): 1455–67. PMID 8830774. 
  • Pulkkinen L, Smith FJ, Shimizu H, et al. (1997). "Homozygous deletion mutations in the plectin gene (PLEC1) in patients with epidermolysis bullosa simplex associated with late-onset muscular dystrophy.". Hum. Mol. Genet. 5 (10): 1539–46. PMID 8894687. 
  • Gress TM, Müller-Pillasch F, Geng M, et al. (1996). "A pancreatic cancer-specific expression profile.". Oncogene 13 (8): 1819–30. PMID 8895530. 
  • Andrä K, Nikolic B, Stöcher M, et al. (1998). "Not just scaffolding: plectin regulates actin dynamics in cultured cells.". Genes Dev. 12 (21): 3442–51. PMID 9808630. 
  • Banwell BL, Russel J, Fukudome T, et al. (1999). "Myopathy, myasthenic syndrome, and epidermolysis bullosa simplex due to plectin deficiency.". J. Neuropathol. Exp. Neurol. 58 (8): 832–46. PMID 10446808. 
  • Geerts D, Fontao L, Nievers MG, et al. (1999). "Binding of integrin alpha6beta4 to plectin prevents plectin association with F-actin but does not interfere with intermediate filament binding.". J. Cell Biol. 147 (2): 417–34. PMID 10525545. 
  • Stegh AH, Herrmann H, Lampel S, et al. (2000). "Identification of the cytolinker plectin as a major early in vivo substrate for caspase 8 during CD95- and tumor necrosis factor receptor-mediated apoptosis.". Mol. Cell. Biol. 20 (15): 5665–79. PMID 10891503. 
  • Bauer JW, Rouan F, Kofler B, et al. (2001). "A compound heterozygous one amino-acid insertion/nonsense mutation in the plectin gene causes epidermolysis bullosa simplex with plectin deficiency.". Am. J. Pathol. 158 (2): 617–25. PMID 11159198. 
  • Henzler T, Harmache A, Herrmann H, et al. (2001). "Fully functional, naturally occurring and C-terminally truncated variant human immunodeficiency virus (HIV) Vif does not bind to HIV Gag but influences intermediate filament structure.". J. Gen. Virol. 82 (Pt 3): 561–73. PMID 11172097. 
  • Nakano A, Pulkkinen L, Murrell D, et al. (2001). "Epidermolysis bullosa with congenital pyloric atresia: novel mutations in the beta 4 integrin gene (ITGB4) and genotype/phenotype correlations.". Pediatr. Res. 49 (5): 618–26. PMID 11328943. 
  • Brown MJ, Hallam JA, Liu Y, et al. (2001). "Cutting edge: integration of human T lymphocyte cytoskeleton by the cytolinker plectin.". J. Immunol. 167 (2): 641–5. PMID 11441066. 
  • Koss-Harnes D, Høyheim B, Anton-Lamprecht I, et al. (2002). "A site-specific plectin mutation causes dominant epidermolysis bullosa simplex Ogna: two identical de novo mutations.". J. Invest. Dermatol. 118 (1): 87–93. doi:10.1046/j.0022-202x.2001.01591.x. PMID 11851880. 

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Proteins of the cytoskeleton
Microfilaments
Intermediate filaments
type 1 and 2 (Cytokeratin, type I, type II) - type 3 (Desmin, GFAP, Peripherin, Vimentin) - type 4 (Internexin, Nestin, Neurofilament, Synemin, Syncoilin) - type 5 (Lamin A, B)
Microtubules
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