Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Chromatin-associated sphingomyelin: metabolism in relation to cell function.

E Albi1, M P Viola-Magni

  • 1Department of Biochemical Sciences and Molecular Biotechnology, Physiopathology, Policlinico Monteluce, Perugia, Italy.

Cell Biochemistry and Function
|August 12, 2003
PubMed
Summary

This study investigates the presence and role of sphingomyelin in chromatin. Earlier work suggested sphingomyelin was a contaminant, but recent findings confirm it is a functional component of chromatin. Researchers used radioiodination and electron microscopy to track sphingomyelin in chromatin. They found sphingomyelin levels changed during cell differentiation and the cell cycle. Sphingomyelin co-localized with RNA in active transcription regions. Enzymes like sphingomyelinase and synthase were active in chromatin, matching sphingomyelin changes. When sphingomyelin was hydrolyzed, RNA became vulnerable to degradation. The study suggests sphingomyelin may protect RNA from RNase digestion. These findings indicate sphingomyelin plays a role in RNA processing and stabilization in the nucleus.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Additional booster doses in patients with chronic lymphocytic leukemia induce humoral and cellular immune responses to SARS-CoV-2 similar to natural infection regardless ongoing treatments: A study by ERIC, the European Research Initiative on CLL.

American journal of hematology·2024
Same author

Vitamin D receptor expression and acid sphingomyelinase activity in prefrontal region of a learning animal model.

Archives italiennes de biologie·2020
Same author

<i>In Vitro</i> Protective Effects of <i>Lycium barbarum</i> Berries Cultivated in Umbria (Italy) on Human Hepatocellular Carcinoma Cells.

BioMed research international·2016
Same author

Reinterpretation of mouse thyroid changes under space conditions: the contribution of confinement to damage.

Astrobiology·2014
Same author

Observing the mouse thyroid sphingomyelin under space conditions: a case study from the MDS mission in comparison with hypergravity conditions.

Astrobiology·2012
Same author

The thyroid lobes: the different twins.

Archives of biochemistry and biophysics·2011

Area of Science:

  • Cell biology with lipid metabolism
  • Molecular genetics in transcriptional regulation
  • Biochemistry of nuclear structure

Background:

The presence of sphingomyelin in chromatin has been debated for decades. Initial histochemical studies suggested phospholipids, especially sphingomyelin, were part of chromatin. However, many researchers argued these findings were due to contamination during chromatin isolation. Later studies using radioiodination confirmed that phospholipids were absent in isolated chromatin but present in nuclear membranes. These results suggested sphingomyelin might be part of a distinct nuclear fraction. Recent evidence shows sphingomyelin levels change during cell differentiation and the cell cycle. This variation correlates with sphingomyelinase and synthase activity in chromatin. Sphingomyelin co-localizes with RNA in nuclear regions. These findings challenge earlier assumptions about chromatin composition and function.

Purpose Of The Study:

This study aimed to clarify the role of sphingomyelin in chromatin and its relationship to RNA transcription. Researchers sought to determine whether sphingomyelin is a contaminant or a functional component of chromatin. They also investigated how sphingomyelin levels change during cell differentiation and the cell cycle. The study examined the localization of sphingomyelin in relation to RNA and enzymes like sphingomyelinase and synthase. Researchers tested whether sphingomyelin protects RNA from degradation. The goal was to understand how sphingomyelin metabolism influences nuclear processes. The study also aimed to determine if sphingomyelin is present in nuclear complexes beyond DNA and proteins. The findings could help explain how RNA is processed and stabilized in the nucleus.

Keywords:
Chromatin sphingomyelinRNA transcriptionNuclear lipid metabolismCell differentiation

Frequently Asked Questions

The authors propose sphingomyelin may protect RNA from RNase digestion in chromatin.

Electron microscopy and bromo-uridine labeling showed sphingomyelin co-localized with RNA in active transcription regions.

Hydrolysis of sphingomyelin made RNA sensitive to RNase, suggesting it normally protects RNA from degradation.

Radioiodination and DNase/RNase digestion were used to isolate and label chromatin.

Sphingomyelin levels decreased in the S-phase of regenerating liver or cultured cells.

Related Experiment Videos

Main Methods:

The study used radioiodination to label hepatocyte nuclei and isolate chromatin. Researchers analyzed phospholipid composition using biochemical methods. They tracked sphingomyelin levels during cell differentiation and the cell cycle. Electron microscopy was used to visualize sphingomyelin localization. Bromo-uridine labeling helped identify regions of active transcription. DNase and RNase digestion was used to isolate nuclear complexes. Researchers tested the effect of sphingomyelin hydrolysis on RNA stability. The activity of sphingomyelinase and synthase was measured in chromatin. These methods allowed the team to assess sphingomyelin’s role in RNA protection and transcription.

Main Results:

Sphingomyelin was found in chromatin but not in isolated membranes. Levels increased during cell differentiation and decreased in the S-phase. Sphingomyelinase and synthase activity matched these changes. Sphingomyelin co-localized with RNA in active transcription regions. Bromo-uridine labeling showed sphingomyelin and RNA were present in the same areas. Nuclear complexes contained RNA and sphingomyelin after digestion. Hydrolysis of sphingomyelin made RNA sensitive to RNase. These findings suggest sphingomyelin protects RNA from degradation. The study confirms sphingomyelin is a functional component of chromatin. The results indicate sphingomyelin may play a role in RNA processing.

Conclusions:

The study confirms sphingomyelin is present in chromatin and not just a contaminant. Sphingomyelin levels change with cell differentiation and the cell cycle. Enzymes like sphingomyelinase and synthase are active in chromatin. Sphingomyelin co-localizes with RNA in transcription regions. Hydrolysis of sphingomyelin makes RNA vulnerable to RNase. These findings suggest sphingomyelin may protect RNA from degradation. The authors propose sphingomyelin helps stabilize RNA in the nucleus. The study supports the idea that sphingomyelin is part of RNA processing.

The authors suggest these enzymes regulate sphingomyelin levels in chromatin during cell processes.