Related Experiment Video
Updated: Aug 9, 2026
18:25
Live Imaging Assay for Assessing the Roles of Ca2+ and Sphingomyelinase in the Repair of Pore-forming Toxin Wounds
Published on: August 25, 2013
Caenorhabditis elegans contains two distinct acid sphingomyelinases
X Lin1, M O Hengartner, R Kolesnick
1Laboratory of Signal Transduction, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
The Journal of Biological Chemistry
|June 11, 1998
Summary
The nematode C. elegans has two acid sphingomyelinases (ASMs), ASM-1 and ASM-2, unlike other organisms. These enzymes differ in secretion, activity, and developmental expression, suggesting an ASM gene family.
Area of Science:
- Biochemistry
- Molecular Biology
- Genetics
Background:
- Acid sphingomyelinase (ASM) plays a role in cellular stress signaling.
- Previously, only murine and human ASMs were characterized at the molecular level.
- These enzymes share 82% amino acid identity and originate from a conserved gene.
Purpose of the Study:
- To investigate the presence and characteristics of ASMs in Caenorhabditis elegans.
- To determine if C. elegans possesses ASM activity and identify the encoding genes.
- To compare C. elegans ASMs with their human and murine counterparts.
Main Methods:
- Bioinformatic analysis to identify ASM genes in C. elegans.
- Gene expression analysis during different developmental stages.
- Transfection of C. elegans ASM genes into COS-7 cells to assess protein localization and enzymatic activity.
- Biochemical assays to determine enzyme kinetics and cofactor requirements.
Main Results:
- C. elegans possesses two distinct ASM genes, ASM-1 and ASM-2, with approximately 30% amino acid identity to each other and to mammalian ASMs.
- ASM-1 is primarily expressed in embryos, while ASM-2 is expressed in postembryonic stages.
- ASM-1 is predominantly secreted and enzymatically active without cofactors, whereas ASM-2 shows partial secretion and requires Zn2+ for full activity.
- C. elegans lacks detectable neutral sphingomyelinase activity.
Conclusions:
- C. elegans is the first organism identified with two distinct acid sphingomyelinases, suggesting the existence of an ASM gene family.
- Differential expression and activity profiles of ASM-1 and ASM-2 indicate specialized roles in C. elegans development and stress response.
- The conserved domains and features suggest a shared evolutionary origin and functional importance of ASMs across species.
