Microtubule-associated protein

Function

Microtubule-associated protein light chain 3 (LC3) is recruited to autophagosomal membranes during autophagy[1]. The human LC3B is cleaved after synthesis to expose a C-terminal glycine which binds via a phospholipid anchor to autophagosomal vesicle membranes during autophagy. Thus detection of LC3 is a reliable method for monitoring autophagy. The microtubule-associated proteins are classified as 2 types. Type 1 includes MAP1 and type 2 includes MAP2, MAP4 and Tau protein.

  • MAP1 are classical microtubule-associated proteins which bind along microtubule lattice[2].
  • Tau protein is the principal component of the tangles found in Alzheimer's disease. It is hyperphosphorylated on serines and threonines[3].
  • Microtubule-associated protein RP/EB family member 1 (MAPRE1) is involved in the regulation of microtubule structure and chromosome stability. It associates with dynactin and the spindle during mitosis[4].
  • Microtubule-associated protein RP/EB family member 3 (MAPRE3) localizes to the cytoplasmic microtubule network and binds a homolog of the adenomatous polyposis coli tumor suppressor gene[5].

Disease

Microtubule-associated protein Tau is associated with Alzheimer Disease. Tau forms abnormal aggregates in patients' tissues. Mutations in tau protein are associated with neurodegenerative diseases like frontotemporal dementia[6].

Structural highlights

[7]. Water molecules are shown as red spheres.

3D Structures of microtubule-associated protein

Microtubule-associated protein 3D structures


Human microtubule-associated protein light chain 3B (cyan) complex with sequestosome peptide (green) (PDB code 2zjd)

Drag the structure with the mouse to rotate

ReferencesReferences

  1. Maccioni RB, Cambiazo V. Role of microtubule-associated proteins in the control of microtubule assembly. Physiol Rev. 1995 Oct;75(4):835-64. PMID:7480164
  2. Halpain S, Dehmelt L. The MAP1 family of microtubule-associated proteins. Genome Biol. 2006;7(6):224. PMID:16938900
  3. Lebouvier T, Scales TM, Williamson R, Noble W, Duyckaerts C, Hanger DP, Reynolds CH, Anderton BH, Derkinderen P. The microtubule-associated protein tau is also phosphorylated on tyrosine. J Alzheimers Dis. 2009;18(1):1-9. doi: 10.3233/JAD-2009-1116. PMID:19542604 doi:http://dx.doi.org/10.3233/JAD-2009-1116
  4. Buligescu L, Lenkei R, Ciontea M, Dan EM. [Significance of anti-albumin antibodies in chronic liver disease]. Rev Med Interna Neurol Psihiatr Neurochir Dermatovenerol Med Interna. 1977, Jul-Aug;29(4):363-70. PMID:22919
  5. Turtola LO. Enamel microhardness and fluoride uptake underneath fermenting and non-fermenting artificial plaque. Scand J Dent Res. 1977 Sep;85(6):373-9. PMID:22924
  6. Schraen-Maschke S, Dhaenens CM, Delacourte A, Sablonniere B. Microtubule-associated protein tau gene: a risk factor in human neurodegenerative diseases. Neurobiol Dis. 2004 Apr;15(3):449-60. PMID:15056452 doi:http://dx.doi.org/10.1016/j.nbd.2003.12.009
  7. Ichimura Y, Kumanomidou T, Sou YS, Mizushima T, Ezaki J, Ueno T, Kominami E, Yamane T, Tanaka K, Komatsu M. Structural basis for sorting mechanism of p62 in selective autophagy. J Biol Chem. 2008 Aug 15;283(33):22847-57. Epub 2008 Jun 4. PMID:18524774 doi:http://dx.doi.org/M802182200

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Michal Harel, Jaime Prilusky, Alexander Berchansky, Joel L. Sussman