5JCO

Structure and dynamics of single-isoform recombinant neuronal human tubulin

Summary for 5JCO

• Entry DOI: 10.2210/pdb5jco/pdb
• EMDB information: 8150
• Descriptor: Tubulin beta-3 chain, Tubulin alpha-1A chain, PHOSPHOMETHYLPHOSPHONIC ACID GUANYLATE ESTER, ... (5 entities in total)
• Functional Keywords: microtubules, tubulin, single isoform, recombinant, dynamic instability, structural protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 12
• Total formula weight: 585311.68

Authors

Vemu, A.,Atherton, J.,Spector, J.O.,Szyk, A.,Moores, C.A.,Roll-Mecak, A. (deposition date: 2016-04-15, release date: 2016-05-04, Last modification date: 2024-03-06)

Primary citation

Vemu, A.,Atherton, J.,Spector, J.O.,Szyk, A.,Moores, C.A.,Roll-Mecak, A.
Structure and Dynamics of Single-isoform Recombinant Neuronal Human Tubulin.
J.Biol.Chem., 291:12907-12915, 2016

PubMed Abstract: Microtubules are polymers that cycle stochastically between polymerization and depolymerization, i.e. they exhibit "dynamic instability." This behavior is crucial for cell division, motility, and differentiation. Although studies in the last decade have made fundamental breakthroughs in our understanding of how cellular effectors modulate microtubule dynamics, analysis of the relationship between tubulin sequence, structure, and dynamics has been held back by a lack of dynamics measurements with and structural characterization of homogeneous isotypically pure engineered tubulin. Here, we report for the first time the cryo-EM structure and in vitro dynamics parameters of recombinant isotypically pure human tubulin. α1A/βIII is a purely neuronal tubulin isoform. The 4.2-Å structure of post-translationally unmodified human α1A/βIII microtubules shows overall similarity to that of heterogeneous brain microtubules, but it is distinguished by subtle differences at polymerization interfaces, which are hot spots for sequence divergence between tubulin isoforms. In vitro dynamics assays show that, like mosaic brain microtubules, recombinant homogeneous microtubules undergo dynamic instability, but they polymerize slower and have fewer catastrophes. Interestingly, we find that epitaxial growth of α1A/βIII microtubules from heterogeneous brain seeds is inefficient but can be fully rescued by incorporating as little as 5% of brain tubulin into the homogeneous α1A/βIII lattice. Our study establishes a system to examine the structure and dynamics of mammalian microtubules with well defined tubulin species and is a first and necessary step toward uncovering how tubulin genetic and chemical diversity is exploited to modulate intrinsic microtubule dynamics.

PubMed: 27129203
DOI: 10.1074/jbc.C116.731133

Experimental method

ELECTRON MICROSCOPY (4 Å)