Senescence-associated beta-galactosidase

Hypothetical hydrolase enzyme

galactosidase, beta 1

Identifiers
Symbol| GLB1
Alt. symbols| SA-β-Gal
NCBI gene| 2720
HGNC| 4298
OMIM| 611458
RefSeq| NM_000404
UniProt| P16278
Other data
EC number| 3.2.1.23
Locus| Chr. 3 p22.3
| Search for

Structures| Swiss-model
Domains| InterPro

Senescence-associated beta-galactosidase (SA-β-gal or SABG) is a hypothetical hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides. Senescence-associated beta-galactosidase, along with p16Ink4A, is regarded to be a biomarker of cellular senescence.[1][2]

Its existence was proposed in 1995 by Dimri et al.[3] following the observation that when beta-galactosidase assays were carried out at pH 6.0, only cells in senescence state develop staining. They proposed a cytochemical assay based on production of a blue-dyed precipitate that results from the cleavage of the chromogenic substrate X-Gal, which stains blue when cleaved by galactosidase. Since then, even more specific quantitative assays were developed for its detection at pH 6.0.[4][5][6]

Today this phenomenon is explained by the overexpression and accumulation of the endogenous lysosomal beta-galactosidase specifically in senescent cells.[7] Its expression is not required for senescence.[7] However, it remains as the most widely used biomarker for senescent and aging cells, because it is easy to detect and reliable both in situ and in vitro.[citation needed]

## References

[edit]

1. ^ Hall BM, Balan V, Gleiberman AS, Strom E, Krasnov P, Virtuoso LP, Rydkina E, Vujcic S, Balan K, Gitlin I, Leonova K, Polinsky A, Chernova OB, Gudkov AV (2016). "Aging of mice is associated with p16(Ink4a)- and β-galactosidase-positive macrophage accumulation that can be induced in young mice by senescent cells". Aging. 8 (7): 1294–1315\. doi:10.18632/aging.100991. PMC 4993332. PMID 27391570.
2. ^ Hall BM, Balan V, Gleiberman AS, Strom E, Krasnov P, Virtuoso LP, Rydkina E, Vujcic S, Balan K, Gitlin II, Leonovo KI, Consiglio CR, Gollnick SO, et al. (2017). "p16(Ink4a) and senescence-associated β-galactosidase can be induced in macrophages as part of a reversible response to physiological stimuli". Aging. 9 (8). Albany NY: 1867–1884\. doi:10.18632/aging.101268. PMC 5611982. PMID 28768895.
3. ^ Dimri GP, Lee X, Basile G, Acosta M, Scott G, Roskelley C, Medrano EE, Linskens M, Rubelj I, Pereira-Smith O (September 1995). "A biomarker that identifies senescent human cells in culture and in aging skin in vivo". Proc. Natl. Acad. Sci. U.S.A. 92 (20): 9363–7\. Bibcode:1995PNAS...92.9363D. doi:10.1073/pnas.92.20.9363. PMC 40985. PMID 7568133.
4. ^ Bassaneze V, Miyakawa AA, Krieger JE (January 2008). "A quantitative chemiluminescent method for studying replicative and stress-induced premature senescence in cell cultures". Anal. Biochem. 372 (2): 198–203\. doi:10.1016/j.ab.2007.08.016. PMID 17920029.
5. ^ Gary RK, Kindell SM (August 2005). "Quantitative assay of senescence-associated beta-galactosidase activity in mammalian cell extracts". Anal. Biochem. 343 (2): 329–34\. doi:10.1016/j.ab.2005.06.003. PMID 16004951.
6. ^ Itahana K, Campisi J, Dimri GP (2007). "Methods to Detect Biomarkers of Cellular Senescence". Biological Aging. Methods in Molecular Biology. Vol. 371\. Humana Press. pp. 21–31. doi:10.1007/978-1-59745-361-5_3. ISBN 978-1-58829-658-0. PMID 17634571.
7. ^ a b Lee BY, Han JA, Im JS, Morrone A, Johung K, Goodwin EC, Kleijer WJ, DiMaio D, Hwang ES (April 2006). "Senescence-associated beta-galactosidase is lysosomal beta-galactosidase". Aging Cell. 5 (2): 187–95\. doi:10.1111/j.1474-9726.2006.00199.x. hdl:2158/216175. PMID 16626397. S2CID 82432911.

## Further reading

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* Yang NC, Hu ML (October 2005). "The limitations and validities of senescence associated-beta-galactosidase activity as an aging marker for human foreskin fibroblast Hs68 cells". Exp. Gerontol. 40 (10): 813–9\. doi:10.1016/j.exger.2005.07.011. PMID 16154306. S2CID 30500511.

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