Biology:SAFB

Short description: Protein-coding gene in the species Homo sapiens

Generic protein structure example

Scaffold attachment factor B, also known as SAFB, is a gene with homologs that have been studied in humans and mice.

Function

This gene encodes a DNA-binding protein that has specificity for scaffold or matrix attachment region DNA elements (S/MAR DNA). This protein is thought to be involved in attaching the base of chromatin loops to the nuclear matrix but there are conflicting views as to whether this protein is a component of chromatin, the nuclear matrix, or both. Scaffold attachment factors are a subset of nuclear matrix proteins (NMP) with enriched binding to AT-rich S/MAR sequences. The SAF-B protein is thought to serve as a molecular base to assemble a 'transcriptosome complex' in the vicinity of actively transcribed genes. It is involved in the regulation of the heat shock protein 27 transcription and also can act as an estrogen receptor corepressor. This gene is a candidate gene for breast tumorigenesis.

Interactions

SAFB has been shown to interact with:

• Estrogen receptor alpha,
• HNRPD,
• SAFB2, and
• TAF15.

Further reading

• "Scaffold attachment factors SAFB1 and SAFB2: Innocent bystanders or critical players in breast tumorigenesis?". J. Cell. Biochem. 90 (4): 653–61. 2004. doi:10.1002/jcb.10685. PMID 14587024. 
• "Characterization of SAF-A, a novel nuclear DNA binding protein from HeLa cells with high affinity for nuclear matrix/scaffold attachment DNA elements". EMBO J. 11 (9): 3431–40. 1992. doi:10.1002/j.1460-2075.1992.tb05422.x. PMID 1324173. 
• "Purification and molecular cloning of the scaffold attachment factor B (SAF-B), a novel human nuclear protein that specifically binds to S/MAR-DNA". Nucleic Acids Res. 24 (5): 843–9. 1996. doi:10.1093/nar/24.5.843. PMID 8600450. 
• "Novel nuclear matrix protein HET binds to and influences activity of the HSP27 promoter in human breast cancer cells". J. Cell. Biochem. 67 (2): 275–86. 1997. doi:10.1002/(SICI)1097-4644(19971101)67:2<275::AID-JCB13>3.0.CO;2-E. PMID 9328833. 
• "Assignment of SAFB encoding Hsp27 ERE-TATA binding protein (HET)/scaffold attachment factor B (SAF-B) to human chromosome 19 band p13". Cytogenet. Cell Genet. 79 (3–4): 284–5. 1998. doi:10.1159/000134744. PMID 9605873. 
• "SAF-B protein couples transcription and pre-mRNA splicing to SAR/MAR elements". Nucleic Acids Res. 26 (15): 3542–9. 1998. doi:10.1093/nar/26.15.3542. PMID 9671816. 
• "A novel hnRNP protein (HAP/SAF-B) enters a subset of hnRNP complexes and relocates in nuclear granules in response to heat shock". J. Cell Sci. 112 (10): 1465–76. 1999. doi:10.1242/jcs.112.10.1465. PMID 10212141. 
• "Tamoxifen-bound estrogen receptor (ER) strongly interacts with the nuclear matrix protein HET/SAF-B, a novel inhibitor of ER-mediated transactivation". Mol. Endocrinol. 14 (3): 369–81. 2000. doi:10.1210/mend.14.3.0432. PMID 10707955. 
• "Interaction of two multifunctional proteins. Heterogeneous nuclear ribonucleoprotein K and Y-box-binding protein". J. Biol. Chem. 275 (20): 15498–503. 2000. doi:10.1074/jbc.275.20.15498. PMID 10809782. 
• "A nuclear matrix-associated factor, SAF-B, interacts with specific isoforms of AUF1/hnRNP D". Arch. Biochem. Biophys. 380 (2): 228–36. 2000. doi:10.1006/abbi.2000.1938. PMID 10933876. 
• "The STAR/GSG family protein rSLM-2 regulates the selection of alternative splice sites". J. Biol. Chem. 276 (12): 8665–73. 2001. doi:10.1074/jbc.M006851200. PMID 11118435. 
• "High rates of loss of heterozygosity on chromosome 19p13 in human breast cancer". Br. J. Cancer 84 (4): 493–8. 2001. doi:10.1054/bjoc.2000.1606. PMID 11207044. 
• "Cloning and characterization of an alternatively spliced form of SR protein kinase 1 that interacts specifically with scaffold attachment factor-B". J. Biol. Chem. 276 (43): 40175–82. 2001. doi:10.1074/jbc.M104755200. PMID 11509566. 
• "Hsp27 as a Negative Regulator of Cytochrome c Release". Mol. Cell. Biol. 22 (3): 816–34. 2002. doi:10.1128/MCB.22.3.816-834.2002. PMID 11784858. 
• "The tight junction protein ZO-2 localizes to the nucleus and interacts with the heterogeneous nuclear ribonucleoprotein scaffold attachment factor-B". J. Biol. Chem. 278 (4): 2692–700. 2003. doi:10.1074/jbc.M206821200. PMID 12403786. 
• "SAFB2, a new scaffold attachment factor homolog and estrogen receptor corepressor". J. Biol. Chem. 278 (22): 20059–68. 2003. doi:10.1074/jbc.M212988200. PMID 12660241. 
• "Nuclear speckle localisation of the small heat shock protein alpha B-crystallin and its inhibition by the R120G cardiomyopathy-linked mutation". Exp. Cell Res. 287 (2): 249–61. 2003. doi:10.1016/S0014-4827(03)00092-2. PMID 12837281. 
• "CHD1 associates with NCoR and histone deacetylase as well as with RNA splicing proteins". Biochem. Biophys. Res. Commun. 308 (1): 170–6. 2003. doi:10.1016/S0006-291X(03)01354-8. PMID 12890497. 
• "Regulation of Alternative Splicing by SRrp86 and Its Interacting Proteins". Mol. Cell. Biol. 23 (21): 7437–47. 2003. doi:10.1128/MCB.23.21.7437-7447.2003. PMID 14559993.