Microtubule-associated protein 2

Microtubule-associated protein 2 is a protein in humans that is encoded by the MAP2 gene.[5][6]

MAP2
Identifiers
AliasesMAP2, MAP2A, MAP2B, MAP2C, microtubule associated protein 2, MAP-2
External IDsOMIM: 157130; MGI: 97175; HomoloGene: 1779; GeneCards: MAP2; OMA:MAP2 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001039934
NM_008632
NM_001310634

RefSeq (protein)

NP_001035023
NP_001297563
NP_032658

Location (UCSC)Chr 2: 209.42 – 209.73 MbChr 1: 66.21 – 66.48 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

Function

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This gene encodes a protein that belongs to the microtubule-associated protein family. The proteins of this family were originally isolated since they copurify with tubulin in polymerization experiments: tubulin in cell extracts can be made to polymerize to produce microtubules (MT) under the influence of heat and the addition of GTP, and the MT can then be collected by centrifugation. When this is done a series of microtubule associated proteins are collected along with the MT and can be detected by SDS-PAGE and other methods. Brain extracts are rich in several of these proteins, MAP2 being one of these. The single MAP2 gene produces four major transcripts producing four proteins, MAP2A, MAP2B, MAP2C and MAP2D. MAP2A and MAP2B are very high molecular weight proteins, with apparent molecular weight on SDS-PAGE about 250 kDa, while MAP2C and MAP2D are much lower molecular weight forms with apparent SDS-PAGE size about 70 kDa.[7] All forms of MAP2 share a common core sequence which includes MT binding domains, 18 amino acid sequences which are found in other MT associated proteins such as MAP Tau and MAP1B. The MAP2 isoforms are thought to be involved in MT assembly, which is an essential step in neuritogenesis. MAP2 serves to stabilize MT growth by crosslinking MT with intermediate filaments and other MTs. MAP2 isoforms are neuron-specific cytoskeletal proteins enriched in dendrites and perikarya, implicating a role in determining and stabilizing neuronal morphology during neuron development. As a result antibodies to MAP2 are widely used to identify neuronal cells and trace dendritic processes in experimental contexts.

Interactions

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MAP2 has been shown to interact with Grb2,[8][9] NEFL[10] and MYO7A.[11] All MAP2 isoforms bind to microtubules.

 
Neurons were grown in tissue culture and stained with antibody to MAP2 protein in green and MAP tau in red using the immunofluorescence technique. MAP2 is found only in dendrites and perikarya, while tau is found not only in the dendrites and perikarya but also in axons. As a result, axons appear red while the dendrites and perikarya appear yellow, due to superimposition of the red and green signals. DNA is shown in blue using the DAPI stain which highlights the nuclei. Image courtesy EnCor Biotechnology Inc.

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000078018Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000015222Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Neve RL, Harris P, Kosik KS, Kurnit DM, Donlon TA (May 1987). "Identification of cDNA clones for the human microtubule-associated protein tau and chromosomal localization of the genes for tau and microtubule-associated protein 2". Brain Res. 387 (3): 271–80. doi:10.1016/0169-328x(86)90033-1. PMID 3103857.
  6. ^ Kalcheva N, Albala J, O'Guin K, Rubino H, Garner C, Shafit-Zagardo B (December 1995). "Genomic structure of human microtubule-associated protein 2 (MAP-2) and characterization of additional MAP-2 isoforms". Proc Natl Acad Sci U S A. 92 (24): 10894–8. Bibcode:1995PNAS...9210894K. doi:10.1073/pnas.92.24.10894. PMC 40537. PMID 7479905.
  7. ^ "Entrez Gene: MAP2 microtubule-associated protein 2".
  8. ^ Lim RW, Halpain S (July 2000). "Regulated association of microtubule-associated protein 2 (MAP2) with Src and Grb2: evidence for MAP2 as a scaffolding protein". J. Biol. Chem. 275 (27): 20578–87. doi:10.1074/jbc.M001887200. PMID 10781592.
  9. ^ Zamora-Leon SP, Lee G, Davies P, Shafit-Zagardo B (October 2001). "Binding of Fyn to MAP-2c through an SH3 binding domain. Regulation of the interaction by ERK2". J. Biol. Chem. 276 (43): 39950–8. doi:10.1074/jbc.M107807200. PMID 11546790.
  10. ^ Frappier T, Stetzkowski-Marden F, Pradel LA (April 1991). "Interaction domains of neurofilament light chain and brain spectrin". Biochem. J. 275 (Pt 2): 521–7. doi:10.1042/bj2750521. PMC 1150082. PMID 1902666.
  11. ^ Todorov PT, Hardisty RE, Brown SD (March 2001). "Myosin VIIA is specifically associated with calmodulin and microtubule-associated protein-2B (MAP-2B)". Biochem. J. 354 (Pt 2): 267–74. doi:10.1042/0264-6021:3540267. PMC 1221652. PMID 11171103.

Further reading

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