Related Experiment Video
Updated: May 1, 2026
06:23
Detection of Nuclear Blebbing and DNA Leakage in Mammalian Cells by Immunofluorescence
Published on: January 17, 2025
1.2K
Interphase phosphorylation of lamin A
Vitaly Kochin1, Takeshi Shimi2, Elin Torvaldson3
1Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, FIN-20521 Turku, Finland Department of Biosciences, Åbo Akademi University, FIN-20520 Turku, Finland Department of Pathology, Sapporo Medical University, Sapporo, Hokkaido 060-8556, Japan.
Journal of Cell Science
|April 18, 2014
Summary
Nuclear lamins are key structural proteins. Phosphorylation sites on lamin A regulate its structure and dynamics, impacting nuclear integrity and potentially laminopathies.
Area of Science:
- Cell Biology
- Structural Biology
- Biochemistry
Background:
- Nuclear lamins form the nuclear lamina, crucial for structural integrity.
- Lamin A/C gene mutations cause laminopathies, but interphase regulation is unclear.
Purpose of the Study:
- To define the role of phosphorylation in regulating lamin A assembly and organization in interphase cells.
- To identify key phosphorylation sites controlling lamin A structure and dynamics.
Main Methods:
- Site-directed mutagenesis of identified phosphorylation sites.
- Advanced microscopy techniques: fluorescence recovery after photobleaching (FRAP) and fluorescence correlation spectroscopy (FCS).
- Nuclear extraction assays.
Main Results:
- Identified 20 interphase phosphorylation sites on lamin A, with eight being high-turnover sites.
- Discovered three dominant phosphorylation regions controlling lamin A structure and dynamics.
- Observed differential phosphorylation of specific sites in mitotic cells, with one site absent in progerin.
Conclusions:
- Phosphorylation is a major determinant of lamin A structure and dynamics in interphase cells.
- Specific phosphorylation patterns influence lamin A assembly, turnover, and mobility.
- Findings offer insights into laminopathies and Hutchinson-Gilford progeria syndrome pathogenesis.
Related Concept Videos
01:35Disassembly of Intermediate Filaments
2.0K
Intermediate filaments (IFs) do not undergo spontaneous disassembly. Enzymes, kinases, and phosphatases add and remove phosphates from specific sites to regulate their disassembly. The IF concentration in the cytoplasm also regulates the disassembly. If the concentration crosses a threshold, it activates the protein kinases in the vicinity, allowing the phosphorylation of IFs.
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
2.0K
01:31Mechanism of Lamellipodia Formation
3.1K
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
3.1K
02:17Separation of Sister Chromatids
3.6K
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...
At the onset of anaphase, separase, a proteolytic enzyme, is...
3.6K
01:42Actin Polymerization
6.3K
Actin polymerization occurs through the head-to-tail association of binding sites on monomeric actin or G-actin to form filamentous or F-actin. The polymerization can be divided into three phases ̶ nucleation, elongation, and steady-state phase.
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
6.3K
00:55Laminins are the Adhesive Proteins of Basal Lamina
3.4K
Laminins are heterotrimeric proteins with high molecular mass found in the extracellular matrix. Each laminin molecule is composed of three chains, viz. alpha, beta, and gamma, coded by five, four, and three paralogous genes, respectively. Laminins are categories based on the compositions of the three chains.
In humans, the five forms of alpha chains are LAMA 1, LAMA 2, LAMA 3, LAMA 4, and LAMA 5. The four forms of beta chains are LAMB 1, LAMB 2, LAMB 3, and LAMB 4. The three forms of gamma...
In humans, the five forms of alpha chains are LAMA 1, LAMA 2, LAMA 3, LAMA 4, and LAMA 5. The four forms of beta chains are LAMB 1, LAMB 2, LAMB 3, and LAMB 4. The three forms of gamma...
3.4K
00:50Anaphase Promoting Complex
2.5K
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...
2.5K