Senescence-associated beta-galactosidase

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galactosidase, beta 1
Identifiers
Symbol GLB1
Alt. symbols SA-β-Gal
Entrez 2720
HUGO 4298
OMIM 611458
RefSeq NM_000404
UniProt P16278
Other data
Locus Chr. 3 p22.3

Senescence-associated beta-galactosidase (SA-β-gal or SABG) is a hypothetical hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides only in senescent cells.

Its existence was proposed in 1995 by Dimri et al.[1] 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. Since then, even more specific quantitative assays were developed for its detection at pH 6.0.[2][3][4]

Today this phenomenon is explained by the overexpression and accumulation of the endogenous lysosomal beta-galactosidase specifically in senescent cells.[5] Its expression is not required for senescence. 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.

References[edit]

  1. ^ 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. doi:10.1073/pnas.92.20.9363. PMC 40985. PMID 7568133. 
  2. ^ 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. 
  3. ^ 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. 
  4. ^ Itahana K, Campisi J, Dimri GP (2007). "Methods to detect biomarkers of cellular senescence: the senescence-associated beta-galactosidase assay". Methods Mol. Biol. Methods in Molecular Biology 371: 21–31. doi:10.1007/978-1-59745-361-5_3. ISBN 978-1-58829-658-0. PMID 17634571. 
  5. ^ 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. PMID 16626397. 

Further reading[edit]

  • 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. 

External links[edit]