Recombinant Microtubule-Associated Protein 2c Reduces the Dynamic Instability of Individual Microtubules
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- 作者：T. Chris Gamblin ; Kirsten Nachmanoff ; Shelley Halpain ; and Robley C. Williams ; Jr.
- 刊名：Biochemistry
- 出版年：1996
- 出版时间：September 24, 1996
- 年：1996
- 卷：35
- 期：38
- 页码：12576 - 12586
- 全文大小：525K
- 年卷期：v.35,no.38(September 24, 1996)
- ISSN：1520-4995
文摘
The effects of purified recombinant microtubule-associated protein2c (rMAP2c) on the dynamicinstability of microtubules were examined by direct observation ofindividual microtubules in vitro byvideo-enhanced differential interference contrast light microscopy.Microtubules were grown in the absenceor presence of varying concentrations of rMAP2c and were analyzed todetermine growth rates, shorteningrates, and the frequencies of conversion between growing and shorteningphases. We found rMAP2c tostabilize microtubules dramatically. The most notable effect is areduction in both the frequency ofcatastrophes (transitions from growth to shortening) and the meanlength of shortening events: nomicrotubule catastrophes were observed at concentrations of rMAP2c aslow as 1.06 
M in a solution of10 M tubulin. Even at lower rMAP2c concentrations, there is amarked stabilizing effect. As theconcentration of rMAP2c increases, average growth rates increaseslightly, shortening rates decrease, andthe frequency of rescues (transitions from shortening to growth)increases significantly. Together, thesechanges in parameters produce a population of extremely stablemicrotubules in the presence of rMAP2c.This stabilization is consistent with a structural role for MAP2cduring early postnatal neural development.
M in a solution of10 M tubulin. Even at lower rMAP2c concentrations, there is amarked stabilizing effect. As theconcentration of rMAP2c increases, average growth rates increaseslightly, shortening rates decrease, andthe frequency of rescues (transitions from shortening to growth)increases significantly. Together, thesechanges in parameters produce a population of extremely stablemicrotubules in the presence of rMAP2c.This stabilization is consistent with a structural role for MAP2cduring early postnatal neural development.