Related Experiment Video
Updated: May 13, 2026
12:04
Examination of Mitotic and Meiotic Fission Yeast Nuclear Dynamics by Fluorescence Live-cell Microscopy
Published on: June 24, 2019
An auxiliary, membrane-based mechanism for nuclear migration in budding yeast
Marisa Kirchenbauer1, Dimitris Liakopoulos
1Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany.
Molecular Biology of the Cell
|March 1, 2013
Summary
Budding yeast form nuclear protrusions (nucleopodia) before cell division, requiring membrane expansion and DNA replication, not traditional migration pathways. This process aids correct nuclear positioning.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Nuclear shape and movement during the cell cycle are not fully understood.
- Investigating nuclear morphology changes during nuclear migration in budding yeast.
Purpose of the Study:
- To elucidate the mechanisms behind nuclear shape changes during cell division.
- To understand the role of nuclear protrusions (nucleopodia) in nuclear migration.
Main Methods:
- Microscopy to observe nuclear morphology and migration in budding yeast.
- Genetic analysis using mutations in exocyst complex and DNA replication pathways.
- Investigating the role of actin and astral microtubules.
Main Results:
- Nuclear protrusions (nucleopodia) form in preanaphase cells, preceding chromosome insertion into the bud neck.
- Nucleopodia formation is independent of established nuclear migration pathways.
- Nucleopodia require nuclear membrane expansion, actin, and the exocyst complex.
- Exocyst mutations lead to nuclear positioning defects and interact with mutations affecting microtubule-dependent migration.
- Cells unable to perform DNA replication fail to form nucleopodia.
Conclusions:
- Nuclear membrane expansion, DNA replication, and exocyst-dependent anchoring are crucial for nucleopodia formation.
- These factors influence nuclear morphology and facilitate proper nuclear and chromosome positioning relative to the cleavage apparatus.
Related Concept Videos
01:28Yeast 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...
01:32Cytoskeletal Coordination in Cell Migration
A migrating cell changes its shape during the cyclic events of attachment and detachment from the substratum and repositions the cell organelles correspondingly. These complex events are orchestrated by the dynamic cytoskeletal network comprising actin filaments, intermediate filaments, and microtubules. Cytoskeletal crosstalk — the direct and indirect communication between the different components — is crucial for this coordination. Direct communication involves various linker proteins that...
01:43The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
02:50Spindle 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...
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...
01:18Role of Myosin in Cell Migration
Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
02:15The 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...
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...