Microtubules are essential and ubiquitous elements of the cytoskeleton. Their filamentous arrays contribute to an impressive diversity of biologic functions that include cell division, intracellular transport, and the maintenance of cellular architecture. The subunit from which microtubules are assembled is the tubulin heterodimer, which consists of 1 alpha-tubulin and 1 beta-tubulin polypeptide, each of about 50 kD.

Microtubules are essential for various cellular processes including cell division and intracellular organization. Their function depends on their ability to rearrange their distribution at different times and places. Microtubules are dynamic polymers and their behaviour is described as dynamic instability.

The microtubule array has a central role in the regulation of cell shape and polarity during differentiation, chromosome partitioning at mitosis, and intracellular transport. Microtubules undergo rearrangements involving rapid transitions between stable and dynamic states during these processes.

Microtubules mediate adaptation and maintenance of the cytoskeleton. The polymerization and depolymerization of alpha-tubulins (MIM.602529) and beta-tubulins (MIM.191130) controls the assembly and disassembly of microtubules.

Microtubules-associated proteins or MAPs (MIM.600178), regulate the dynamics and stability of microtubules, and different types of MTs contain different MAPs.

Pathology of microtubules

 anomalies of microtubules stability

• anomalies of the protein tau (taupathies)

 cellular cilia dysfunctions

• primary ciliary dyskinesia (DNAH5, DNAH7, DNAH11)
• lateralization defects (situs inversus)
• infertility in men
• Kartagener syndrome

 pathology of MAPs (microtubule-associated proteins)

• taupathies - pathology of the microtubule-associated protein tau (TAU)

 pathology of tubulins
 pathology of tubulin-specific chaperones

See also:

 microtubules stability
 microtubule-associated proteins (MAPs)

• tau protein (TAU)

 MARKs

References

 Guzik BW, Goldstein LS. Microtubule-dependent transport in neurons: steps towards an understanding of regulation, function and dysfunction. Curr Opin Cell Biol. 2004 Aug;16(4):443-50. PMID: #15261678#

 Zheng Y. G protein control of microtubule assembly. Annu Rev Cell Dev Biol. 2004;20:867-94. PMID: #15473863#

 Jordan MA, Wilson L. Microtubules as a target for anticancer drugs. Nat Rev Cancer. 2004 Apr;4(4):253-65. PMID: #15057285#

 Carvalho P, Tirnauer JS, Pellman D. Surfing on microtubule ends. Trends Cell Biol. 2003 May;13(5):229-37. PMID: #12742166#

 Maly IV, Borisy GG. Self-organization of treadmilling microtubules into a polar array. Trends Cell Biol. 2002 Oct ;12(10):462-5. PMID : #12441249#

 Kinoshita K, Habermann B, Hyman AA. XMAP215: a key component of the dynamic microtubule cytoskeleton. Trends Cell Biol. 2002 Jun;12(6):267-73. PMID: #12074886#

 Oakley BR. An abundance of tubulins. Trends Cell Biol. 2000 Dec;10(12):537-42. PMID: #11121746#

 Andersen SS. Spindle assembly and the art of regulating microtubule dynamics by MAPs and Stathmin/Op18. Trends Cell Biol. 2000 Jul;10(7):261-7. PMID: #10856928#