QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 17 July 2006
doi: 10.1242/jcs.03039

This Article Figures Only Full Text Full Text (PDF) Supplementary Material All Versions of this Article: jcs.03039v1 119/15/3238    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JCS Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Venkei, Z. Articles by Szabad, J. Search for Related Content PubMed PubMed Citation Articles by Venkei, Z. Articles by Szabad, J.

4-Tubulin is involved in rapid formation of long microtubules to push apart the daughter centrosomes during earlyx Drosophila embryogenesis

¹ Maternal Effect and Embryogenesis Research Group of the Hungarian Academy of Sciences at the University of Szeged, Faculty of Medicine, Department of Biology, Somogyi B. u. 4, H-6720 Szeged, Hungary
² University of Szeged, Faculty of Medicine, Department of Medical Chemistry, Szeged, Hungary

^* Author for correspondence (e-mail: szabad{at}mdbio.szote.u-szeged.hu)

Accepted 8 May 2006

Although 4-tubulin comprises only about one-fifth of the -tubulin pool in every Drosophila egg, in the absence of 4-tubulin - in eggs of the kavar⁰/- hemizygous females - only a tassel of short microtubules forms with two barely separated daughter centrosomes. We report that 4-tubulin is enriched in the long microtubules that embrace the nuclear envelope and suggest that they push apart daughter centrosomes along the nuclear perimeter during the initial cleavage divisions. In vitro tubulin polymerization showed that 4-tubulin is required for rapid tubulin polymerization. Since tubulin polymerization is slow inside eggs of the kavar⁰/- females, only short microtubules can form within the 4 to 5 minutes allowed for the process. A tassel of short microtubules with two barely separated centrosomes forms in every egg of the Kavar^18c/+ females, in which the cytoplasm contains both wild-type and Kavar^18c-encoded 4-tubulin with an E82K amino acid substitution (E82K-4-tubulin). E82K-4-tubulin is incorporated into the microtubules and renders them unstable. When injected into wild-type early cleavage embryos E82K-4-tubulin slows down the formation of long microtubules and the separation of the daughter centrosomes. Surprisingly, when injected into late cleavage embryos E82K-4-tubulin is non-toxic. Similarly, in the neuroblasts, ectopically expressed E82K-4-tubulin becomes incorporated into the microtubules that grow sufficiently long and function normally.

Key words: -tubulin, Interpolar microtubules, Centrosome separation, Dominant-negative mutation, Drosophila embryogenesis

Related articles in JCS:

4-Tubulin ups the pace

JCS 2006 119: 1501. [Full Text]  

This article has been cited by other articles:

				A. Forer The diversity of cytoplasmic microtubules J. Cell Sci., January 1, 2008; 121(1): 7 - 9. [Full Text] [PDF]

				J. Zhang and T. L. Megraw Proper Recruitment of {gamma}-Tubulin and D-TACC/Msps to Embryonic Drosophila Centrosomes Requires Centrosomin Motif 1 Mol. Biol. Cell, October 1, 2007; 18(10): 4037 - 4049. [Abstract] [Full Text] [PDF]