- Separase
protein
Name=extra spindle pole bodies homolog 1 (S. cerevisiae)
caption=
width=
HGNCid=16856
Symbol=ESPL1
AltSymbols=
EntrezGene=9700
OMIM=604143
RefSeq=NM_012291
UniProt=Q14674
PDB=
ECnumber=3.4.22.49
Chromosome=12
Arm=q
Band=13.13
LocusSupplementaryData=Separase is a
cysteine protease responsible for triggeringanaphase by hydrolysingcohesin which is theprotein responsible for binding sisterchromatid s duringmetaphase .When the cell is not dividing, separase is prevented from cleaving cohesin through its association with another protein,
securin . On the signal for anaphase, the securin is ubiquitinated and hydrolysed, releasing active separase.Esp1
Esp1 is a separin
protein that cleaves thecohesin subunitScc1 , thus allowingsister chromatids to separate at the onset of anaphase duringmitosis . Esp1 is coded by esp1-1 and is regulated by thesecurin Pds1 . During mitosis, sister chromatids comprise the duplicated genetic material of a dividing cell. The two sister chromatids are bound together up until the beginning of anaphase, at which point themitotic spindle pulls the two sister chromatids apart, leaving each of the two daughter cells with an equivalent number of sister chromatids. The proteins which bind to the two sister chromatids, disallowing any premature sister chromatid separation, are apart of thecohesin protein family. One of these cohesin proteins crucial for sister chromatid cohesion is Scc1. For proper onset of anaphase, the protein Esp1 cleaves Scc1, thus allowing the sister chromatids to separate. [cite journal|url=http://www.nature.com/nature/journal/v400/n6739/full/400037a0.html|author= Uhlmann et. al |year= 1999|title=Sister-chromatid Separation at Anaphase-onset is Promoted by Cleavage of Scc1 |journal=Nature |volume=400|pages=37–42|doi= 10.1038/21831 ]While Esp1 was initially dubbed a separin protein, it is now thought to be a
protease , on account of itscatalytic function. Because of this, Esp1 is thought to be in theseparase family.The role of Esp1 was discovered by
Frank Uhlmann ,Friedrick Lottspeich , andKim Nasmyth in their paper "Sister-chromatids separation at anaphase-onset is promoted by cleavage of the cohesin subunit Scc1" which was published in the July 1999 issue of "Nature".References
External links
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* http://www.ncbi.nih.gov/entrez/query.fcgi?db=nucleotide&cmd=search&term=L07289&doptcmdl=GenBank
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