Effects of organic acids on tubulin polymerization and associated GTP hydrolysis

Biochemistry ◽  
1982 ◽  
Vol 21 (3) ◽  
pp. 503-509 ◽  
Author(s):  
Ernest Hamel ◽  
Anthony A. Del Campo ◽  
Michael C. Lowe ◽  
Phyllis G. Waxman ◽  
Chii M. Lin
Keyword(s):  
Organic Acids ◽  
Tubulin Polymerization ◽  
Gtp Hydrolysis

scholarly journals Slow Polymerization of Mycobacterium tuberculosis FtsZ

2000 ◽  
Vol 182 (14) ◽  
pp. 4028-4034 ◽  
Author(s):  
E. Lucile White ◽  
Larry J. Ross ◽  
Robert C. Reynolds ◽  
Lainne E. Seitz ◽  
Georgia D. Moore ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Mycobacterium Tuberculosis ◽  
Tubulin Polymerization ◽  
Gtpase Activity ◽  
Gtp Hydrolysis ◽  
Minimum Concentration ◽  
E Coli ◽  
Cell Division Protein ◽  
Mycobacterial Protein

ABSTRACT The essential cell division protein, FtsZ, from Mycobacterium tuberculosis has been expressed in Escherichia coliand purified. The recombinant protein has GTPase activity typical of tubulin and other FtsZs. FtsZ polymerization was studied using 90° light scattering. The mycobacterial protein reaches maximum polymerization much more slowly (∼10 min) than E. coliFtsZ. Depolymerization also occurs slowly, taking 1 h or longer under most conditions. Polymerization requires both Mg2+and GTP. The minimum concentration of FtsZ needed for polymerization is 3 μM. Electron microscopy shows that polymerized M. tuberculosis FtsZ consists of strands that associate to form ordered aggregates of parallel protofilaments. Ethyl 6-amino-2,3-dihydro-4-phenyl-1H-pyrido[4,3-b][1,4]diazepin-8-ylcarbamate (SRI 7614), an inhibitor of tubulin polymerization synthesized at Southern Research Institute, inhibits M. tuberculosis FtsZ polymerization, inhibits GTP hydrolysis, and reduces the number and sizes of FtsZ polymers.

Mechanism of GTP hydrolysis in tubulin polymerization: characterization of the kinetic intermediate microtubule-GDP-Pi using phosphate analogs

Biochemistry ◽  
1989 ◽  
Vol 28 (4) ◽  
pp. 1783-1791 ◽  
Author(s):  
Marie France Carlier ◽  
Dominique Didry ◽  
Colette Simon ◽  
Dominique Pantaloni
Keyword(s):  
Tubulin Polymerization ◽  
Gtp Hydrolysis ◽  
Kinetic Intermediate

scholarly journals Effect of plant tubulin kinetic diversification on microtubule lengths

2021 ◽  
Author(s):  
Kunalika Jain ◽  
Megha Roy ◽  
Chaitanya A. Athale
Keyword(s):  
Dynamic Instability ◽  
Critical Concentration ◽  
High Rate ◽  
Tubulin Polymerization ◽  
Gtp Hydrolysis ◽  
Animal Brain ◽  
Evolutionary Diversification ◽  
Kinetic Rates ◽  
Hydrolysis Rates ◽  
Plant Tubulin

Microtubules (MTs) are dynamic polymers vital for cellular physiology. Bulk tubulin polymerization is nucleation dependent, while individual filaments exhibit 'dynamic instability' driven by GTP hydrolysis rates. Although MTs assembled from well-studied animal brain tubulins have very comparable nucleation and GTP-hydrolysis rates, the kinetic rates of evolutionarily more distant species could diverge. Here we focus on a plant tubulin, the legume Vigna sp. (mung bean) to test the effect of kinetic diversification on MT polymerization. We activity purify tubulin from seedlings and find MT filaments are fewer and shorter than animal brain tubulin. We find mung tubulin polymerization kinetics is nucleation dependent with a high rate of GTP hydrolysis and a critical concentration lower than previously reported for tubulins. A computational model of the kinetics based on the relative influence of rates of nucleation and hydrolysis demonstrates increased rates of hydrolysis can affect MT filament numbers and their lengths, as compared to increasing nucleation rates. Our approach provides a framework to compare the effect of evolutionary diversification of MT nucleation and elongation.

Thermodynamics of tubulin polymerization into zinc sheets: Assembly is not regulated by GTP hydrolysis

Biochemistry ◽  
1993 ◽  
Vol 32 (13) ◽  
pp. 3405-3413 ◽  
Author(s):  
Ronald Melki ◽  
Marie France Carlier
Keyword(s):  
Tubulin Polymerization ◽  
Gtp Hydrolysis

Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

1977 ◽  
Vol 35 ◽  
pp. 460-461
Author(s):  
Tai-Te Chao ◽  
John Sullivan ◽  
Awtar Krishan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Transmission Electron Microscopy ◽  
Tubulin Polymerization ◽  
Vinca Alkaloids ◽  
Antimitotic Activity ◽  
Transmission Electron ◽  
Flow Microfluorometry ◽  
Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

Analysis of the Mechanism of Microtubule Dynamic Instability Using a UV Microbeam to Sever Elongating Microtubules

1988 ◽  
Vol 46 ◽  
pp. 122-123
Author(s):  
R.A Walker ◽  
S. Inoue ◽  
E.D. Salmon
Keyword(s):  
Dynamic Instability ◽  
Microtubule Dynamic ◽  
Gtp Hydrolysis ◽  
Abrupt Transition ◽  
Microtubule Associated Proteins ◽  
Asymmetrical Structure ◽  
Associated Proteins

Microtubules polymerized in vitro from tubulin purified free of microtubule-associated proteins exhibit dynamic instability (1,2,3). Free microtubule ends exist in persistent phases of elongation or rapid shortening with infrequent, but, abrupt transitions between these phases. The abrupt transition from elongation to rapid shortening is termed catastrophe and the abrupt transition from rapid shortening to elongation is termed rescue. A microtubule is an asymmetrical structure. The plus end grows faster than the minus end. The frequency of catastrophe of the plus end is somewhat greater than the minus end, while the frequency of rescue of the plus end in much lower than for the minus end (4).The mechanism of catastrophe is controversial, but for both the plus and minus microtubule ends, catastrophe is thought to be dependent on GTP hydrolysis. Microtubule elongation occurs by the association of tubulin-GTP subunits to the growing end. Sometime after incorporation into an elongating microtubule end, the GTP is hydrolyzed to GDP, yielding a core of tubulin-GDP capped by tubulin-GTP (“GTP-cap”).

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