Related Experiment Video

Updated: Jul 14, 2026

Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast
11:19

Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast

Published on: February 20, 2017

ASPM and citron kinase co-localize to the midbody ring during cytokinesis

Murugan Paramasivam1, Yoon Jeung Chang, Joseph J LoTurco

  • 1Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269, USA.

Cell Cycle (Georgetown, Tex.)
|May 31, 2007
PubMed

Insights

Mutations in abnormal spindle-like microcephaly associated (ASPM) and citron kinase (CITK) cause microcephaly. ASPM also localizes to the midbody ring, interacting with CITK, suggesting coordinated cell division in neurogenesis.

Area of Science:

  • Cell Biology
  • Developmental Neuroscience
  • Genetics

Background:

  • Primary microcephaly is linked to mutations in ASPM and CITK, proteins crucial for neurogenesis.
  • ASPM is vital for proliferative cell division, localizing to spindle poles.
  • CITK is essential for cellular abscission, found at the cytokinesis furrow and midbody ring.

Purpose of the Study:

  • To investigate the localization and interaction of ASPM and CITK during mammalian cell division.
  • To explore the role of ASPM's C-terminus in midbody localization and its implications for microcephaly.

Main Methods:

  • Immunofluorescence microscopy to determine protein localization.
  • Co-immunoprecipitation assays to assess protein interactions.
  • Analysis of GFP-tagged ASPM fragments to map functional domains.

Main Results:

  • ASPM localizes to the midbody ring in mammalian cells, co-localizing and interacting with CITK.
  • The C-terminus of ASPM is crucial for midbody localization, while the N-terminus targets centrosomes and spindle poles.
  • Other microcephaly-associated proteins (CENPJ, CDK5RAP2) also localize to midbodies.

Conclusions:

  • ASPM's dual localization to spindle poles and midbody ring suggests a role in coordinating cell division stages.
  • The interaction between ASPM and CITK highlights a conserved mechanism for regulating neurogenesis.
  • Findings support a model where spindle dynamics and cellular abscission are tightly coordinated during neurogenesis.

More Related Videos

Reconstitution of Basic Mitotic Spindles in Spherical Emulsion Droplets10:52

Reconstitution of Basic Mitotic Spindles in Spherical Emulsion Droplets

Published on: August 13, 2016

Manipulation and Analysis of Cell Cycle-Dependent Processes in Budding Yeast08:13

Manipulation and Analysis of Cell Cycle-Dependent Processes in Budding Yeast

Published on: September 26, 2025

Related Concept Videos

The Contractile Ring02:15

The Contractile Ring

Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle.
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
The Contractile Ring02:15

The Contractile Ring

Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle.
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
Spindle Assembly02:50

Spindle Assembly

Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
Separation of Sister Chromatids02:17

Separation of Sister Chromatids

At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
The Spindle Assembly Checkpoint02:19

The Spindle Assembly Checkpoint

The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Anaphase Promoting Complex00:50

Anaphase Promoting Complex

The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...