hTPX2 is required for normal spindle morphology and centrosome integrity during vertebrate cell division

Sarah C. Garrett, Kristi Auer, Duane A. Compton, Tarun M. Kapoor

Research output: Contribution to journalArticle

111 Citations (Scopus)

Abstract

Bipolar spindle formation is essential for the accurate segregation of genetic material during cell division. Although centrosomes influence the number of spindle poles during mitosis, motor and non-motor microtubule-associated proteins (MAPs) also play key roles in determining spindle morphology [1]. TPX2 is a novel MAP also characterized in Xenopus cell-free extracts [2, 3]. To examine hTPX2 (human TPX2) function in human cells, we used siRNA to knock-down its expression and found that cells lacking hTPX2 arrest in mitosis with multipolar spindles. NuMA, γ-tubulin, and centrin localize to each pole, and nocodazole treatment of cells lacking hTPX2 demonstrates that the localization of γ-tubulin to multiple spindle poles requires intact microtubules. Furthermore, we show that the formation of monopolar microtubule arrays in human cell extracts does not require hTPX2, demonstrating that the mechanism by which hTPX2 promotes spindle bipolarity is independent of activities focusing microtubule minus ends at spindle poles. Finally, inhibition of the kinesin Eg5 in hTPX2-depleted cells leads to monopolar spindles, indicating that Eg5 function is necessary for multipolar spindle formation in the absence of hTPX2. Our observations reveal a structural role for hTPX2 in spindles and provide evidence for a balance between microtubule-based motor forces and structural spindle components.

Original languageEnglish (US)
Pages (from-to)2055-2059
Number of pages5
JournalCurrent Biology
Volume12
Issue number23
DOIs
StatePublished - Dec 2002
Externally publishedYes

Fingerprint

centrosomes
Centrosome
Cell Division
Vertebrates
cell division
Poles
vertebrates
Cells
Microtubule-Associated Proteins
microtubules
Tubulin
Spindle Poles
Microtubules
Nocodazole
Kinesin
Sulfamethoxazole Drug Combination Trimethoprim
Small Interfering RNA
cells
tubulin
Cell Extracts

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

hTPX2 is required for normal spindle morphology and centrosome integrity during vertebrate cell division. / Garrett, Sarah C.; Auer, Kristi; Compton, Duane A.; Kapoor, Tarun M.

In: Current Biology, Vol. 12, No. 23, 12.2002, p. 2055-2059.

Research output: Contribution to journalArticle

Garrett, Sarah C. ; Auer, Kristi ; Compton, Duane A. ; Kapoor, Tarun M. / hTPX2 is required for normal spindle morphology and centrosome integrity during vertebrate cell division. In: Current Biology. 2002 ; Vol. 12, No. 23. pp. 2055-2059.
@article{b9d6ee43172745a1b7fda42de9b6c46a,
title = "hTPX2 is required for normal spindle morphology and centrosome integrity during vertebrate cell division",
abstract = "Bipolar spindle formation is essential for the accurate segregation of genetic material during cell division. Although centrosomes influence the number of spindle poles during mitosis, motor and non-motor microtubule-associated proteins (MAPs) also play key roles in determining spindle morphology [1]. TPX2 is a novel MAP also characterized in Xenopus cell-free extracts [2, 3]. To examine hTPX2 (human TPX2) function in human cells, we used siRNA to knock-down its expression and found that cells lacking hTPX2 arrest in mitosis with multipolar spindles. NuMA, γ-tubulin, and centrin localize to each pole, and nocodazole treatment of cells lacking hTPX2 demonstrates that the localization of γ-tubulin to multiple spindle poles requires intact microtubules. Furthermore, we show that the formation of monopolar microtubule arrays in human cell extracts does not require hTPX2, demonstrating that the mechanism by which hTPX2 promotes spindle bipolarity is independent of activities focusing microtubule minus ends at spindle poles. Finally, inhibition of the kinesin Eg5 in hTPX2-depleted cells leads to monopolar spindles, indicating that Eg5 function is necessary for multipolar spindle formation in the absence of hTPX2. Our observations reveal a structural role for hTPX2 in spindles and provide evidence for a balance between microtubule-based motor forces and structural spindle components.",
author = "Garrett, {Sarah C.} and Kristi Auer and Compton, {Duane A.} and Kapoor, {Tarun M.}",
year = "2002",
month = "12",
doi = "10.1016/S0960-9822(02)01277-0",
language = "English (US)",
volume = "12",
pages = "2055--2059",
journal = "Current Biology",
issn = "0960-9822",
publisher = "Cell Press",
number = "23",

}

TY - JOUR

T1 - hTPX2 is required for normal spindle morphology and centrosome integrity during vertebrate cell division

AU - Garrett, Sarah C.

AU - Auer, Kristi

AU - Compton, Duane A.

AU - Kapoor, Tarun M.

PY - 2002/12

Y1 - 2002/12

N2 - Bipolar spindle formation is essential for the accurate segregation of genetic material during cell division. Although centrosomes influence the number of spindle poles during mitosis, motor and non-motor microtubule-associated proteins (MAPs) also play key roles in determining spindle morphology [1]. TPX2 is a novel MAP also characterized in Xenopus cell-free extracts [2, 3]. To examine hTPX2 (human TPX2) function in human cells, we used siRNA to knock-down its expression and found that cells lacking hTPX2 arrest in mitosis with multipolar spindles. NuMA, γ-tubulin, and centrin localize to each pole, and nocodazole treatment of cells lacking hTPX2 demonstrates that the localization of γ-tubulin to multiple spindle poles requires intact microtubules. Furthermore, we show that the formation of monopolar microtubule arrays in human cell extracts does not require hTPX2, demonstrating that the mechanism by which hTPX2 promotes spindle bipolarity is independent of activities focusing microtubule minus ends at spindle poles. Finally, inhibition of the kinesin Eg5 in hTPX2-depleted cells leads to monopolar spindles, indicating that Eg5 function is necessary for multipolar spindle formation in the absence of hTPX2. Our observations reveal a structural role for hTPX2 in spindles and provide evidence for a balance between microtubule-based motor forces and structural spindle components.

AB - Bipolar spindle formation is essential for the accurate segregation of genetic material during cell division. Although centrosomes influence the number of spindle poles during mitosis, motor and non-motor microtubule-associated proteins (MAPs) also play key roles in determining spindle morphology [1]. TPX2 is a novel MAP also characterized in Xenopus cell-free extracts [2, 3]. To examine hTPX2 (human TPX2) function in human cells, we used siRNA to knock-down its expression and found that cells lacking hTPX2 arrest in mitosis with multipolar spindles. NuMA, γ-tubulin, and centrin localize to each pole, and nocodazole treatment of cells lacking hTPX2 demonstrates that the localization of γ-tubulin to multiple spindle poles requires intact microtubules. Furthermore, we show that the formation of monopolar microtubule arrays in human cell extracts does not require hTPX2, demonstrating that the mechanism by which hTPX2 promotes spindle bipolarity is independent of activities focusing microtubule minus ends at spindle poles. Finally, inhibition of the kinesin Eg5 in hTPX2-depleted cells leads to monopolar spindles, indicating that Eg5 function is necessary for multipolar spindle formation in the absence of hTPX2. Our observations reveal a structural role for hTPX2 in spindles and provide evidence for a balance between microtubule-based motor forces and structural spindle components.

UR - http://www.scopus.com/inward/record.url?scp=18844464851&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=18844464851&partnerID=8YFLogxK

U2 - 10.1016/S0960-9822(02)01277-0

DO - 10.1016/S0960-9822(02)01277-0

M3 - Article

VL - 12

SP - 2055

EP - 2059

JO - Current Biology

JF - Current Biology

SN - 0960-9822

IS - 23

ER -