Microtubule Markers

Microtubules are one of the three main cytoskeletal elements found in eukaryotic cells, along with actin and intermediate filaments. They play crucial roles in various cellular processes, including defining cell morphology and organization, cell polarity, mitotic spindle formation, cilia and flagella motility, and intracellular transport. Microtubules are polarized, hollow polymers that self-assemble from α-tubulin and β-tubulin proteins and feature a fast-growing plus end and a slow-growing minus end. α-tubulin and β-tubulin monomers heterodimerize into linear α/β-tubulin protofilaments. Typically, 13 of these protofilaments associate laterally to form the basic tube structure of a microtubule, with a diameter of around 25 nanometers. Polymerization occurs through the addition of α/β-tubulin dimers at the growing plus end, where β-tubulin is exposed. Microtubules can range in length from 1 to 100 microns. Both α-tubulin and β-tubulin bind GTP, and tubulin-GTP is required for microtubule polymerization. As α/β-tubulin dimers join the growing microtubule end, β-tubulin-bound GTP is hydrolyzed. However, GTP hydrolysis destabilizes the microtubule wall. Microtubules are likely stabilized at their growing end by a GTP cap, a region where tubulin-GTP has not yet been hydrolyzed. This dynamic balance between growth and shrinkage is a fundamental property of microtubules called dynamic instability. This feature is crucial for the rapid reorganization of the microtubule cytoskeleton. Microtubule-binding proteins can influence microtubule structure and modulate polymerization. Some proteins, such as CLASP and EB1, promote polymerization, while others, such as severing proteins like katanin, promote depolymerization. Other microtubule-binding proteins include capping proteins, bundlers, and cytoskeletal integrators. Tubulins can undergo posttranslational modification, including phosphorylation, acetylation, detyrosination, and sumoylation, which alters the binding affinity between microtubules and microtubule-binding proteins. For example, detyrosination inhibits the binding of the plus end-tracking protein EB1. In addition to α-tubulin and β-tubulin, other tubulin family members – δ-, ε-, and γ-tubulin – are found in unique microtubule-associated structures, such as cilia, flagella, and centrioles. γ-tubulin in particular plays an important role in nucleating the growth of new microtubule structures. The interphase microtubule array is important for defining cell shape and organization. Microtubules in the interphase array serve as tracks for motor-driven intracellular transport, mediated by the microtubule motors kinesin and dynein. The organization of microtubules varies significantly between different cell types. In radially organized cells, the plus ends of microtubules are oriented toward the cell periphery, with the minus ends located at the microtubule-organizing center. In other cell types, such as vertebrate polarized epithelial cells, microtubules run parallel to the cell axis, with minus ends located at the apical membrane and plus ends at the basal membrane. We offer a wide range of microtubule markers including alpha Tubulin antibodies, beta III Tubulin antibodies, and GCP4 antibodies, that are validated for use in multiple applications including flow cytometry, immunocytochemistry (ICC), immunohistochemistry (IHC), enzyme-linked immunosorbent assay (ELISA), and western blotting (WB).