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Microtubule Dynamics

Microtubules are highly-dynamic structural and functional intracellular highways. The term cytoskeleton conjures up an image of rigid, immutable, and permanent structure. In reality, the cytoskeleton is a highly dynamic interconnected network composed of three different principal components: microtubules (polymerized tubulin dimers), microfilaments (polymerized actin), and intermediate filaments. Microtubules are the largest cytoskeletal components. They play a role in nearly every cellular process. They give structural stability and form to an otherwise amorphous cell. They are the principal components in an interconnected intracellular “highway” by which all manner cellular cargo may be shuttled via a bustling network of molecular motor proteins. During mitosis, microtubule contraction, focused at one of two mitotic spindles, provides the force necessary to divide chromosomes.

The ever changing nature of the cellular microenvironment necessitates adaptability, particularly during development. Microtubules and other cytoskeletal components facilitate this adaptability by virtue of their polymeric structure. The fundamental unit of the microtubule is a tubulin dimer, composed of one alpha tubulin-subunit, and one corresponding beta-tubulin subunit. These dimers polymerize to form a hollow, tubular structure approximately 24nm wide. The natural state of unmodified tubulin is one of constant flux, with a nearly equal rate of polymerization and depolymerization. Several common GTPase families like Rac and Rho promote microtubule assembly indirectly by facilitating GDP/GTP exchange on regulatory members that effect assembly and disassembly of tubulin dimers. Other microtubule stabilizers take a more direct approach. Microtubule associated proteins like MAP1, MAP2, MAP4, or MAPtau bind polymerized microtubules stabilize the polymerized form, promoting assembly and microtubule growth. Most MAPs are activated by phosphorylation, and MAPK (map kinase) phosphorylation cascades add an additional layer of control to the process of microtubule assembly.

Conversely, cells have several different ways to regulate microtubule disassembly. Direct methods for promoting disassembly include components like Stathmin, which binds alpha/beta-tubulin dimers and prevents them from polymerizing. Microtubule severing enzymes like Katanin are able to break microtubules in the middle of their structure, while Kinesin I family members like KIF2 walk along microtubules and promote “fraying” and depolymerization.

Microtubule-associated proteins

CLASP1 (Cytoplasmic Linker Associated Protein 1):

CLASPs, such as CLASP1, are nonmotor microtubule-associated proteins that interact with CLIPs (e.g., CLIP170\; MIM 179838). CLASP1 is involved in the regulation of microtubule dynamics at the kinetochore and throughout the spindle (Maiato et al., 2003 [PubMed 12837247]).[supplied by OMIM, Mar 2008].   More...

MAPT (Microtubule-Associated Protein tau):

This gene encodes the microtubule-associated protein tau (MAPT) whose transcript undergoes complex, regulated alternative splicing, giving rise to several mRNA species. MAPT transcripts are differentially expressed in the nervous system, depending on stage of neuronal maturation and neuron type. MAPT gene mutations have been associated with several neurodegenerative disorders such as...   More...
Antigens in this category:
CLIP1 (CAP-GLY Domain Containing Linker Protein 1): CLIP1 antibodies CLIP1 ELISA Kits  
CLIP2 (CAP-GLY Domain Containing Linker Protein 2): CLIP2 antibodies CLIP2 ELISA Kits CLIP2 Proteins
CLASP2 (Cytoplasmic Linker Associated Protein 2): CLASP2 antibodies CLASP2 ELISA Kits CLASP2 Proteins
MAP1A (Microtubule-Associated Protein 1A): MAP1A antibodies MAP1A ELISA Kits MAP1A Proteins
MAP1B (Microtubule-Associated Protein 1B): MAP1B antibodies MAP1B ELISA Kits  
MAP4 (Microtubule-Associated Protein 4): MAP4 antibodies MAP4 ELISA Kits MAP4 Proteins

Tubulins

Tuba1a - TUBA1A

Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha-chain.   More...

TUBB (Tubulin, beta):

beta 5-tubulin\; polymerizes to form microtubules\; member of a family of structural proteins [RGD, Feb 2006].   More...

TUBA4A (Tubulin, alpha 4a):

Microtubules of the eukaryotic cytoskeleton perform essential and diverse functions and are composed of a heterodimer of alpha and beta tubulin. The genes encoding these microtubule constituents are part of the tubulin superfamily, which is composed of six distinct families. Genes from the alpha, beta and gamma tubulin families are found in all eukaryotes. The alpha and beta tubulins represent...   More...

TUBE1 (Tubulin, epsilon 1):

This gene encodes a member of the tubulin superfamily. This protein localizes to the centriolar sub-distal appendages that are associated with the older of the two centrioles after centrosome duplication. This protein plays a central role in organization of the microtubules during centriole duplication. A pseudogene of this gene is found on chromosome 5.[provided by RefSeq, Jan 2009].   More...
Antigens in this category:
TUBA1 - alpha Tubulin: TUBA1 antibodies    
LOC732582 - Tubulin A: LOC732582 antibodies    
TUBA1B (Tubulin, alpha 1B): TUBA1B antibodies TUBA1B ELISA Kits TUBA1B Proteins
TUBA1C (Tubulin, alpha 1c): TUBA1C antibodies TUBA1C ELISA Kits TUBA1C Proteins
TUBA3E (Tubulin, alpha 3e): TUBA3E antibodies   TUBA3E Proteins
TUBA8 (Tubulin, alpha 8): TUBA8 antibodies TUBA8 ELISA Kits TUBA8 Proteins
TUBA3C (Tubulin, Alpha, 3C): TUBA3C antibodies TUBA3C ELISA Kits TUBA3C Proteins
TUBB1 (Tubulin, beta 1): TUBB1 antibodies TUBB1 ELISA Kits TUBB1 Proteins
TUBB2A (Tubulin, beta 2A): TUBB2A antibodies TUBB2A ELISA Kits TUBB2A Proteins
TUBB2B (Tubulin, beta 2B): TUBB2B antibodies TUBB2B ELISA Kits TUBB2B Proteins
TUBb6 (Tubulin, beta 6): TUBb6 antibodies TUBb6 ELISA Kits TUBb6 Proteins
TUBB2C (Tubulin, Beta, 2C): TUBB2C antibodies TUBB2C ELISA Kits TUBB2C Proteins
TUBB3 (Tubulin, Beta, 3): TUBB3 antibodies TUBB3 ELISA Kits TUBB3 Proteins
TUBB5 (Tubulin, Beta, 5): TUBB5 antibodies TUBB5 ELISA Kits TUBB5 Proteins
TUBD1 (Tubulin, delta 1): TUBD1 antibodies TUBD1 ELISA Kits TUBD1 Proteins
TUBG1 (Tubulin, gamma 1): TUBG1 antibodies TUBG1 ELISA Kits TUBG1 Proteins
TUBG2 (Tubulin, gamma 2): TUBG2 antibodies TUBG2 ELISA Kits TUBG2 Proteins

Stabilization/Assembly

CLIP1 (CAP-GLY Domain Containing Linker Protein 1):

The protein encoded by this gene links endocytic vesicles to microtubules. This gene is highly expressed in Reed-Sternberg cells of Hodgkin disease. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2011].   More...

CDC42 (Cell Division Cycle 42 (GTP Binding Protein, 25kDa)):

The protein encoded by this gene is a small GTPase of the Rho-subfamily, which regulates signaling pathways that control diverse cellular functions including cell morphology, migration, endocytosis and cell cycle progression. This protein is highly similar to Saccharomyces cerevisiae Cdc 42, and is able to complement the yeast cdc42-1 mutant. The product of oncogene Dbl was reported to...   More...

CLASP1 (Cytoplasmic Linker Associated Protein 1):

CLASPs, such as CLASP1, are nonmotor microtubule-associated proteins that interact with CLIPs (e.g., CLIP170\; MIM 179838). CLASP1 is involved in the regulation of microtubule dynamics at the kinetochore and throughout the spindle (Maiato et al., 2003 [PubMed 12837247]).[supplied by OMIM, Mar 2008].   More...
Antigens in this category:
CLIP2 (CAP-GLY Domain Containing Linker Protein 2): CLIP2 antibodies CLIP2 ELISA Kits CLIP2 Proteins
CLASP2 (Cytoplasmic Linker Associated Protein 2): CLASP2 antibodies CLASP2 ELISA Kits CLASP2 Proteins
MAP1A (Microtubule-Associated Protein 1A): MAP1A antibodies MAP1A ELISA Kits MAP1A Proteins
MAP1B (Microtubule-Associated Protein 1B): MAP1B antibodies MAP1B ELISA Kits  
MAP4 (Microtubule-Associated Protein 4): MAP4 antibodies MAP4 ELISA Kits MAP4 Proteins
MAPT (Microtubule-Associated Protein tau): MAPT antibodies MAPT ELISA Kits MAPT Proteins
RHOA (Ras Homolog Gene Family, Member A): RHOA antibodies RHOA ELISA Kits RHOA Proteins
ROCK1 (rho-Associated, Coiled-Coil Containing Protein Kinase 1): ROCK1 antibodies ROCK1 ELISA Kits ROCK1 Proteins
ROCK2 (rho-Associated, Coiled-Coil Containing Protein Kinase 2): ROCK2 antibodies ROCK2 ELISA Kits ROCK2 Proteins

Destabilization/Disassembly

FIGNL1 (Fidgetin-Like 1):

May regulate osteoblast proliferation and differentiation (By similarity).   More...

KIF2C (Kinesin Family Member 2C):

The protein encoded by this gene is a member of kinesin-like protein family. Proteins of this family are microtubule-dependent molecular motors that transport organelles within cells and move chromosomes during cell division. This protein is important for anaphase chromosome segregation and may be required to coordinate the onset of sister centromere separation. [provided by RefSeq, Jul 2008].   More...

vps4b - VPS4B

The protein encoded by this gene is a member of the AAA protein family (ATPases associated with diverse cellular activities), and is the homolog of the yeast Vps4 protein. In humans, two paralogs of the yeast protein have been identified. The former share a high degree of aa sequence similarity with each other, and also with yeast Vps4 and mouse Skd1 proteins. Mouse Skd1 (suppressor of K+...   More...
Antigens in this category:
EML2 (Echinoderm Microtubule Associated Protein Like 2): EML2 antibodies EML2 ELISA Kits EML2 Proteins
KATNA1 (Katanin P60 (ATPase Containing) Subunit A 1): KATNA1 antibodies KATNA1 ELISA Kits KATNA1 Proteins
KATNB1 (Katanin P80 (WD Repeat Containing) Subunit B 1): KATNB1 antibodies KATNB1 ELISA Kits KATNB1 Proteins
KIF2B (Kinesin Family Member 2B): KIF2B antibodies KIF2B ELISA Kits KIF2B Proteins
KIF2A - Kinesin Heavy Chain Member 2A: KIF2A antibodies KIF2A ELISA Kits KIF2A Proteins
SPAST - Spastin: SPAST antibodies SPAST ELISA Kits SPAST Proteins
STMN1 - Stathmin 1: STMN1 antibodies STMN1 ELISA Kits STMN1 Proteins
VPS4A (Vacuolar Protein Sorting 4 Homolog A (S. Cerevisiae)): VPS4A antibodies VPS4A ELISA Kits VPS4A Proteins