STAG2

Cohesin subunit SA-2 (SA2) is a protein that in humans is encoded by the STAG2 gene.[5][6] SA2 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2 whereas in meiosis, cohesin is formed of SMC3, SMC1B, REC8 and SA3.

STAG2
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 4PJU, 4PJW, 4PK7
Identifiers
Aliases	STAG2, SA-2, SA2, SCC3B, bA517O1.1, stromal antigen 2, NEDXCF, MKMS, HPE13
External IDs	OMIM: 300826 MGI: 1098583 HomoloGene: 38206 GeneCards: STAG2
Gene location (Human) Chr. X chromosome (human)[1] Band Xq25 Start 123,960,212 bp[1] End 124,422,664 bp[1]
Gene location (Mouse) Chr. X chromosome (mouse)[2] Band X|X A4 Start 42,149,317 bp[2] End 42,277,185 bp[2]
RNA expression pattern More reference expression data
Gene ontology Molecular function • GO:0001948 protein binding • chromatin binding Cellular component • cytosol • membrane • chromosome • nucleoplasm • chromatin • chromosome, centromeric region • cell nucleus • cohesin complex • nuclear matrix • mitotic spindle pole Biological process • chromosome segregation • cell division • negative regulation of DNA endoreduplication • GO:0007126 meiotic cell cycle • cell cycle • sister chromatid cohesion • regulation of mitotic spindle assembly Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	10735	20843
Ensembl	ENSG00000101972	ENSMUSG00000025862
UniProt	Q8N3U4	O35638
RefSeq (mRNA)	NM_001042749 NM_001042750 NM_001042751 NM_001282418 NM_006603 NM_001375375	NM_001077712 NM_001290713 NM_021465 NM_001358225
RefSeq (protein)	NP_001036214 NP_001036215 NP_001036216 NP_001269347 NP_006594 NP_001362304	NP_001071180 NP_001277642 NP_067440 NP_001345154
Location (UCSC)	Chr X: 123.96 – 124.42 Mb	Chr X: 42.15 – 42.28 Mb
PubMed search	[3]	[4]
Wikidata
View/Edit Human View/Edit Mouse

STAG2 is frequently mutated in a range of cancers [7] and several other disorders.

Function

SA2 is part of the cohesin complex, which is a structure that holds the sister chromatids together after DNA replication.[8] STAG2 has been shown to interact with STAG1.[9]

Role in Disease

Of the cohesin complex, STAG2 is the subunit where the most variants have been reported in cancer. [10] This is thought to be because this gene is located in the X chromosome, therefore only one mutation is needed to inactivate it.[11]

References

1. GRCh38: Ensembl release 89: ENSG00000101972 - Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000025862 - Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. Carramolino L, Lee BC, Zaballos A, Peled A, Barthelemy I, Shav-Tal Y, Prieto I, Carmi P, Gothelf Y, González de Buitrago G, Aracil M, Márquez G, Barbero JL, Zipori D (August 1997). "SA-1, a nuclear protein encoded by one member of a novel gene family: molecular cloning and detection in hemopoietic organs". Gene. 195 (2): 151–9. doi:10.1016/S0378-1119(97)00121-2. PMID 9305759.
6. "Entrez Gene: STAG2 stromal antigen 2".
7. De Koninck M, Losada A (December 2016). "Cohesin Mutations in Cancer". Cold Spring Harbor Perspectives in Medicine. 6 (12): a026476. doi:10.1101/cshperspect.a026476. PMC 5131750. PMID 27742736.
8. Mehta, Gunjan D.; Kumar, Ravinder; Srivastava, Sanjeeva; Ghosh, Santanu Kumar (2013-08-02). "Cohesin: Functions beyond sister chromatid cohesion". FEBS Letters. 587 (15): 2299–2312. doi:10.1016/j.febslet.2013.06.035. ISSN 1873-3468. PMID 23831059.
9. Sumara I, Vorlaufer E, Gieffers C, Peters BH, Peters JM (November 2000). "Characterization of vertebrate cohesin complexes and their regulation in prophase". The Journal of Cell Biology. 151 (4): 749–62. doi:10.1083/jcb.151.4.749. PMC 2169443. PMID 11076961.
10. Cosmic. "STAG2 Gene - COSMIC". cancer.sanger.ac.uk. Retrieved 2018-02-13.
11. Kim, Jung-Sik; He, Xiaoyuan; Orr, Bernardo; Wutz, Gordana; Hill, Victoria; Peters, Jan-Michael; Compton, Duane A.; Waldman, Todd (2016-02-12). "Intact Cohesion, Anaphase, and Chromosome Segregation in Human Cells Harboring Tumor-Derived Mutations in STAG2". PLOS Genetics. 12 (2): e1005865. doi:10.1371/journal.pgen.1005865. ISSN 1553-7404. PMC 4752446. PMID 26871722.