Purification of a WD repeat protein, EMAP, that promotes microtubule dynamics through an inhibition of rescue.

The Journal of Biological Chemistry
D R HamillK A Suprenant

Abstract

The major microtubule-associated protein in echinoderms is a 77-kDa, WD repeat protein, called EMAP. EMAP-related proteins have been identified in sea urchins, starfish, sanddollars, and humans. We describe the purification of sea urchin EMAP and demonstrate that EMAP binding to microtubules is saturable at a molar ratio of 1 mol of EMAP to 3 mol of tubulin dimer. Unlike MAP-2, MAP-4, or tau proteins, EMAP binding to microtubules is not lost by cleavage of tubulin with subtilisin. In addition to binding to the microtubule polymer, EMAP binds to tubulin dimers in a 1:1 molar ratio. The abundance of EMAP in the egg suggests that it could function to regulate microtubule assembly. To test this hypothesis, we examined the effects of EMAP on the dynamic instability of microtubules nucleated from axoneme fragments as monitored by video-enhanced differential interference contrast microscopy. Addition of 2.2 microM EMAP to 21 microM tubulin results in a slight increase in the elongation and shortening velocities at the microtubule plus ends but not at the minus ends. Significantly, EMAP inhibits the frequency of rescue 8-fold without producing a change in the frequency of catastrophe. These results indicate that EMAP, unlike brain micr...Continue Reading

References

Sep 1, 1979·Proceedings of the National Academy of Sciences of the United States of America·H TowbinJ Gordon
Nov 25, 1977·Journal of Molecular Biology·D B MurphyG G Borisy
Sep 18, 1992·Cell·P PierreT E Kreis
Oct 1, 1992·Molecular Biology of the Cell·D N DrechselM W Kirschner
Jan 1, 1991·Annual Review of Cell Biology·V I Gelfand, A D Bershadsky
Sep 1, 1991·The Journal of Cell Biology·E M MandelkowR A Milligan
Jan 1, 1989·Cell Motility and the Cytoskeleton·K A SuprenantL E Hammer
Jun 1, 1989·Neuron·G LeeK S Kosik
Jan 1, 1986·Methods in Enzymology·B J Schnapp
Oct 1, 1983·Proceedings of the National Academy of Sciences of the United States of America·R B Vallee, G S Bloom
Jan 1, 1982·Methods in Cell Biology·C W BellI R Gibbons
Oct 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·L SerranoJ Avila
Dec 1, 1984·The Journal of Cell Biology·W M SaxtonJ R McIntosh
Nov 15, 1984·Nature·T Mitchison, M Kirschner
Dec 1, 1983·Proceedings of the National Academy of Sciences of the United States of America·T L Hill, M F Carlier
Jan 1, 1993·Cell Motility and the Cytoskeleton·L Cassimeris
Jan 1, 1993·Cell Motility and the Cytoskeleton·R J Kowalski, R C Williams

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Citations

May 26, 1999·Cell Motility and the Cytoskeleton·L KniplingJ Wolff
Oct 14, 2000·Annual Review of Cell and Developmental Biology·K H Downing
Oct 14, 2011·American Journal of Physiology. Renal Physiology·Silvia MedranoR Ariel Gomez
Jun 26, 2004·Cell Structure and Function·T J ItohH Hotani
Apr 8, 2014·Proceedings of the National Academy of Sciences of the United States of America·Mark W RichardsRichard Bayliss
Jun 3, 1999·The Journal of Cell Biology·J S TirnauerD Pellman
Jun 8, 2004·Traffic·Matthew A Berezuk, Trina A Schroer
Jun 25, 2013·Molecular Reproduction and Development·Valérie VergéGérard Peaucellier
Jul 1, 2004·Gene·V O'ConnorP J French
Aug 8, 2006·Experimental Cell Research·Marc PollmannHans-Juergen Heidebrecht
Aug 31, 2000·Annual Review of Biochemistry·E Nogales
Jul 10, 2001·Annual Review of Biophysics and Biomolecular Structure·E Nogales
Feb 13, 2013·Chembiochem : a European Journal of Chemical Biology·Keya ZhangJun Yin
Jun 17, 2003·The Journal of Biological Chemistry·Juliana S Popova, Mark M Rasenick
Nov 6, 2001·The Journal of Biological Chemistry·Bernd EichenmullerKathy A Suprenant
Mar 30, 2020·Scientific Reports·G B CollinP M Nishina
Dec 3, 2016·Biochemical Society Transactions·Andrew M FryRichard Bayliss
Oct 1, 1998·Biochemical and Biophysical Research Communications·Q LiK A Suprenant

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