Related Experiment Video

Updated: May 21, 2026

Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast
11:19

Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast

Published on: February 20, 2017

Fission yeast Dma1 requires RING domain dimerization for its ubiquitin ligase activity and mitotic checkpoint

Alyssa E Johnson1, Scott E Collier, Melanie D Ohi

  • 1Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.

The Journal of Biological Chemistry
|June 7, 2012
PubMed

Insights

The E3 ubiquitin ligase Dma1 in fission yeast forms a stable homodimer through its RING domain. This dimerization is crucial for Dma1

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The E3 ubiquitin ligase Dma1 regulates cytokinesis in fission yeast.
  • Proper chromosome attachment to the mitotic spindle is essential for cell division.
  • Dma1's function is linked to the mitotic checkpoint and cell cycle progression.

Purpose of the Study:

  • To investigate the structural and functional significance of Dma1 dimerization.
  • To determine the role of the C-terminal RING domain in Dma1 homodimerization.
  • To elucidate how Dma1 dimerization impacts its cellular localization and E3 ligase activity.

Main Methods:

  • Homodimerization assays using the Dma1 RING domain.
  • Site-directed mutagenesis to identify key residues for dimerization.
  • Localization studies using microscopy.
  • Assessment of E3 ligase activity and mitotic checkpoint function.

Main Results:

  • The Dma1 C-terminal RING domain forms a stable homodimer.
  • Specific residues in the C-terminal tail are required for dimer stability.
  • Dma1 dimerization is essential for its localization to spindle pole bodies and the cell division site.
  • Dimerization is critical for Dma1's E3 ligase activity and mitotic checkpoint function.

Conclusions:

  • Dma1 forms an obligate dimer via its RING domain, essential for ubiquitin transfer.
  • Dma1 dimerization is a prerequisite for its proper cellular function during mitosis.
  • This finding supports the model that many RING E3 ligases function as dimers.

More Related Videos

Microscopy of Fission Yeast Sexual Lifecycle07:47

Microscopy of Fission Yeast Sexual Lifecycle

Published on: March 9, 2016

Examination of Mitotic and Meiotic Fission Yeast Nuclear Dynamics by Fluorescence Live-cell Microscopy12:04

Examination of Mitotic and Meiotic Fission Yeast Nuclear Dynamics by Fluorescence Live-cell Microscopy

Published on: June 24, 2019

Related Concept Videos

Yeast Signaling01:28

Yeast Signaling

Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
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...
Protein Complexes with Interchangeable Parts01:57

Protein Complexes with Interchangeable Parts

Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
M-Cdk Drives Transition Into Mitosis02:15

M-Cdk Drives Transition Into Mitosis

Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
M-Cdk Drives Transition Into Mitosis02:15

M-Cdk Drives Transition Into Mitosis

Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Restarting Stalled Replication Forks02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...