| Structural highlights
Disease
[SFPQ_HUMAN] Translocation renal cell carcinoma. A chromosomal aberration involving SFPQ may be a cause of papillary renal cell carcinoma (PRCC). Translocation t(X;1)(p11.2;p34) with TFE3.
Function
[SFPQ_HUMAN] DNA- and RNA binding protein, involved in several nuclear processes. Essential pre-mRNA splicing factor required early in spliceosome formation and for splicing catalytic step II, probably as a heteromer with NONO. Binds to pre-mRNA in spliceosome C complex, and specifically binds to intronic polypyrimidine tracts. Involved in regulation of signal-induced alternative splicing. During splicing of PTPRC/CD45, a phosphorylated form is sequestered by THRAP3 from the pre-mRNA in resting T-cells; T-cell activation and subsequent reduced phosphorylation is proposed to lead to release from THRAP3 allowing binding to pre-mRNA splicing regulatotry elements which represses exon inclusion. Interacts with U5 snRNA, probably by binding to a purine-rich sequence located on the 3' side of U5 snRNA stem 1b. May be involved in a pre-mRNA coupled splicing and polyadenylation process as component of a snRNP-free complex with SNRPA/U1A. The SFPQ-NONO heteromer associated with MATR3 may play a role in nuclear retention of defective RNAs. SFPQ may be involved in homologous DNA pairing; in vitro, promotes the invasion of ssDNA between a duplex DNA and produces a D-loop formation. The SFPQ-NONO heteromer may be involved in DNA unwinding by modulating the function of topoisomerase I/TOP1; in vitro, stimulates dissociation of TOP1 from DNA after cleavage and enhances its jumping between separate DNA helices. The SFPQ-NONO heteromer may be involved in DNA non-homologous end joining (NHEJ) required for double-strand break repair and V(D)J recombination and may stabilize paired DNA ends; in vitro, the complex strongly stimulates DNA end joining, binds directly to the DNA substrates and cooperates with the Ku70/G22P1-Ku80/XRCC5 (Ku) dimer to establish a functional preligation complex. SFPQ is involved in transcriptional regulation. Transcriptional repression is mediated by an interaction of SFPQ with SIN3A and subsequent recruitment of histone deacetylases (HDACs). The SFPQ-NONO-NR5A1 complex binds to the CYP17 promoter and regulates basal and cAMP-dependent transcriptional avtivity. SFPQ isoform Long binds to the DNA binding domains (DBD) of nuclear hormone receptors, like RXRA and probably THRA, and acts as transcriptional corepressor in absence of hormone ligands. Binds the DNA sequence 5'-CTGAGTC-3' in the insulin-like growth factor response element (IGFRE) and inhibits IGF-I-stimulated transcriptional activity. Regulates the circadian clock by repressing the transcriptional activator activity of the CLOCK-ARNTL/BMAL1 heterodimer. Required for the transcriptional repression of circadian target genes, such as PER1, mediated by the large PER complex through histone deacetylation.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
Publication Abstract from PubMed
Splicing factor proline/glutamine-rich (SFPQ) is an essential RNA-binding protein that is implicated in many aspects of nuclear function. The structures of SFPQ and two paralogs, non-POU domain-containing octamer-binding protein and paraspeckle component 1, from the Drosophila behavior human splicing protein family have previously been characterized. The unusual arrangement of the four domains, two RNA-recognition motifs (RRMs), a conserved region termed the NonA/paraspeckle (NOPS) domain and a C-terminal coiled coil, in the intertwined dimer provides a potentially unique RNA-binding surface. However, the molecular details of how the four RRMs in the dimeric SFPQ interact with RNA remain to be characterized. Here, a new crystal structure of the dimerization domain of human SFPQ in the C-centered orthorhombic space group C2221 with one monomer in the asymmetric unit is presented. Comparison of the new crystal structure with the previously reported structure of SFPQ and analysis of the solution small-angle X-scattering data revealed subtle domain movements in the dimerization domain of SFPQ, supporting the concept of multiple conformations of SFPQ in equilibrium in solution. The domain movement of RRM1, in particular, may reflect the complexity of the RNA substrates of SFPQ. Taken together, the crystal and solution structure analyses provide a molecular basis for further investigation into the plasticity of nucleic acid binding by SFPQ in the absence of the structure in complex with its cognate RNA-binding partners.
A new crystal structure and small-angle X-ray scattering analysis of the homodimer of human SFPQ.,Hewage TW, Caria S, Lee M Acta Crystallogr F Struct Biol Commun. 2019 Jun 1;75(Pt 6):439-449. doi:, 10.1107/S2053230X19006599. Epub 2019 May 21. PMID:31204691[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Urban RJ, Bodenburg Y, Kurosky A, Wood TG, Gasic S. Polypyrimidine tract-binding protein-associated splicing factor is a negative regulator of transcriptional activity of the porcine p450scc insulin-like growth factor response element. Mol Endocrinol. 2000 Jun;14(6):774-82. PMID:10847580
- ↑ Straub T, Knudsen BR, Boege F. PSF/p54(nrb) stimulates "jumping" of DNA topoisomerase I between separate DNA helices. Biochemistry. 2000 Jun 27;39(25):7552-8. PMID:10858305
- ↑ Akhmedov AT, Lopez BS. Human 100-kDa homologous DNA-pairing protein is the splicing factor PSF and promotes DNA strand invasion. Nucleic Acids Res. 2000 Aug 15;28(16):3022-30. PMID:10931916
- ↑ Mathur M, Tucker PW, Samuels HH. PSF is a novel corepressor that mediates its effect through Sin3A and the DNA binding domain of nuclear hormone receptors. Mol Cell Biol. 2001 Apr;21(7):2298-311. PMID:11259580 doi:http://dx.doi.org/10.1128/MCB.21.7.2298-2311.2001
- ↑ Zhang Z, Carmichael GG. The fate of dsRNA in the nucleus: a p54(nrb)-containing complex mediates the nuclear retention of promiscuously A-to-I edited RNAs. Cell. 2001 Aug 24;106(4):465-75. PMID:11525732
- ↑ Sewer MB, Nguyen VQ, Huang CJ, Tucker PW, Kagawa N, Waterman MR. Transcriptional activation of human CYP17 in H295R adrenocortical cells depends on complex formation among p54(nrb)/NonO, protein-associated splicing factor, and SF-1, a complex that also participates in repression of transcription. Endocrinology. 2002 Apr;143(4):1280-90. PMID:11897684 doi:http://dx.doi.org/10.1210/endo.143.4.8748
- ↑ Bladen CL, Udayakumar D, Takeda Y, Dynan WS. Identification of the polypyrimidine tract binding protein-associated splicing factor.p54(nrb) complex as a candidate DNA double-strand break rejoining factor. J Biol Chem. 2005 Feb 18;280(7):5205-10. Epub 2004 Dec 7. PMID:15590677 doi:http://dx.doi.org/10.1074/jbc.M412758200
- ↑ Heyd F, Lynch KW. Phosphorylation-dependent regulation of PSF by GSK3 controls CD45 alternative splicing. Mol Cell. 2010 Oct 8;40(1):126-37. doi: 10.1016/j.molcel.2010.09.013. PMID:20932480 doi:10.1016/j.molcel.2010.09.013
- ↑ Gozani O, Patton JG, Reed R. A novel set of spliceosome-associated proteins and the essential splicing factor PSF bind stably to pre-mRNA prior to catalytic step II of the splicing reaction. EMBO J. 1994 Jul 15;13(14):3356-67. PMID:8045264
- ↑ Patton JG, Porro EB, Galceran J, Tempst P, Nadal-Ginard B. Cloning and characterization of PSF, a novel pre-mRNA splicing factor. Genes Dev. 1993 Mar;7(3):393-406. PMID:8449401
- ↑ Hewage TW, Caria S, Lee M. A new crystal structure and small-angle X-ray scattering analysis of the homodimer of human SFPQ. Acta Crystallogr F Struct Biol Commun. 2019 Jun 1;75(Pt 6):439-449. doi:, 10.1107/S2053230X19006599. Epub 2019 May 21. PMID:31204691 doi:http://dx.doi.org/10.1107/S2053230X19006599
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