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Updated: May 18, 2026
Using an Extracellular Flux Analyzer to Measure Changes in Glycolysis and Oxidative Phosphorylation during Mouse Sperm Capacitation
Published on: January 22, 2020
Sperm-specific glyceraldehyde-3-phosphate dehydrogenase is expressed in melanoma cells
Irina A Sevostyanova1, Kseniya V Kulikova, Mikhail L Kuravsky
1Lomonosov Moscow State University, Faculty of Bioengineering and Bioinformatics, 119234 Moscow, Russia. irina@genebee.msu.ru
Abstract:
Sperm-specific glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDS) is normally expressed only in sperms, but not in somatic tissues. Analysis of the expression of GAPDS mRNA in different cancer cell lines shows that the content of GAPDS mRNA is enhanced in some lines of melanoma cells. The purpose of the study was to assay melanoma cells for the expression of protein GAPDS. Three different lines of melanoma cells were investigated. By data of Western blotting, all investigated cells contain a 37-kDa fragment of GAPDS polypeptide chain, which corresponds to the enzyme GAPDS lacking N-terminal amino acid sequence that attaches the enzyme to the cytoskeleton of the sperm flagellum. The results suggest that GAPDS is expressed in melanoma cells without N-terminal domain. The immunoprecipitation of proteins from melanoma cell extracts using rabbit polyclonal antibodies against native GAPDS allowed isolation of complexes containing 37-kDa subunit of GAPDS and full-length subunit of somatic glyceraldehyde-3-phosphate dehydrogenase (GAPD). The results indicate that melanoma cells express both isoenzymes, which results in the formation of heterotetrameric complexes. Immunocytochemical staining of melanoma cells revealed native GAPDS in the cytoplasm. It is assumed that the expression of GAPDS in melanoma cells may facilitate glycolysis and prevent the induction of apoptosis.
Insights
Melanoma cells express a sperm-specific enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDS), typically absent in somatic tissues. This aberrant expression may enhance glycolysis and inhibit apoptosis in cancer cells.
Area of Science:
- Biochemistry
- Oncology
- Molecular Biology
Background:
- Sperm-specific glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDS) is normally restricted to sperm cells.
- Elevated GAPDS mRNA levels have been observed in certain melanoma cell lines, suggesting potential protein expression.
Purpose of the Study:
- To investigate the expression of GAPDS protein in melanoma cells.
- To characterize the form and cellular localization of GAPDS in melanoma.
Main Methods:
- Western blotting to detect GAPDS protein fragments.
- Immunoprecipitation to identify protein complexes involving GAPDS.
- Immunocytochemical staining to determine GAPDS localization.
Main Results:
- A 37-kDa fragment of GAPDS, lacking the N-terminal domain, was detected in all investigated melanoma cell lines.
- Melanoma cells express both GAPDS and the somatic isoenzyme (GAPD), forming heterotetrameric complexes.
- Native GAPDS was found in the cytoplasm of melanoma cells.
Conclusions:
- Melanoma cells express a truncated form of GAPDS.
- The co-expression of GAPDS and GAPD in melanoma cells leads to the formation of hybrid enzyme complexes.
- GAPDS expression in melanoma may contribute to enhanced glycolysis and resistance to apoptosis.
