This gene encodes subunit 1 of the splicing factor 3b protein complex. Splicing factor 3b, together with splicing factor 3a and a 12S RNA unit, forms the U2 small nuclear ribonucleoproteins complex (U2 snRNP). The splicing factor 3b/3a complex binds pre-mRNA upstream of the intron's branch site in a sequence independent manner and may anchor the U2 snRNP to the pre-mRNA. Splicing factor 3b is also a component of the minor U12-type spliceosome. The carboxy-terminal two-thirds of subunit 1 have 22 non-identical, tandem HEAT repeats that form rod-like, helical structures. Alternative splicing results in multiple transcript variants encoding different isoforms.[2]
Mutations in this gene have been recurrently seen in cases of advanced chronic lymphocytic leukemia,[8] myelodysplastic syndromes[9] and breast cancer.[10] SF3B1 mutations are found in 60%-80% of patients with refractory anemia with ring sideroblasts (RARS; which is a myelodysplastic syndrome) or RARS with thrombocytosis (RARS-T; which is a myelodysplastic syndrome/myeloproliferative neoplasm). There is also an emerging body of evidence to suggest implications of SF3B1 mutations being involved in orbital melanoma.
↑Boudrez A, Beullens M, Waelkens E, Stalmans W, Bollen M (August 2002). "Phosphorylation-dependent interaction between the splicing factors SAP155 and NIPP1". The Journal of Biological Chemistry. 277 (35): 31834–41. doi:10.1074/jbc.M204427200. PMID12105215.
↑Quesada V, Conde L, Villamor N, Ordóñez GR, Jares P, Bassaganyas L, Ramsay AJ, Beà S, Pinyol M, Martínez-Trillos A, López-Guerra M, Colomer D, Navarro A, Baumann T, Aymerich M, Rozman M, Delgado J, Giné E, Hernández JM, González-Díaz M, Puente DA, Velasco G, Freije JM, Tubío JM, Royo R, Gelpí JL, Orozco M, Pisano DG, Zamora J, Vázquez M, Valencia A, Himmelbauer H, Bayés M, Heath S, Gut M, Gut I, Estivill X, López-Guillermo A, Puente XS, Campo E, López-Otín C (January 2012). "Exome sequencing identifies recurrent mutations of the splicing factor SF3B1 gene in chronic lymphocytic leukemia". Nature Genetics. 44 (1): 47–52. doi:10.1038/ng.1032. PMID22158541.
Dias Neto E, Correa RG, Verjovski-Almeida S, Briones MR, Nagai MA, da Silva W, Zago MA, Bordin S, Costa FF, Goldman GH, Carvalho AF, Matsukuma A, Baia GS, Simpson DH, Brunstein A, de Oliveira PS, Bucher P, Jongeneel CV, O'Hare MJ, Soares F, Brentani RR, Reis LF, de Souza SJ, Simpson AJ (March 2000). "Shotgun sequencing of the human transcriptome with ORF expressed sequence tags". Proceedings of the National Academy of Sciences of the United States of America. 97 (7): 3491–6. doi:10.1073/pnas.97.7.3491. PMC16267. PMID10737800.
Das R, Zhou Z, Reed R (May 2000). "Functional association of U2 snRNP with the ATP-independent spliceosomal complex E". Molecular Cell. 5 (5): 779–87. doi:10.1016/S1097-2765(00)80318-4. PMID10882114.
Boudrez A, Beullens M, Waelkens E, Stalmans W, Bollen M (August 2002). "Phosphorylation-dependent interaction between the splicing factors SAP155 and NIPP1". The Journal of Biological Chemistry. 277 (35): 31834–41. doi:10.1074/jbc.M204427200. PMID12105215.
Golas MM, Sander B, Will CL, Lührmann R, Stark H (May 2003). "Molecular architecture of the multiprotein splicing factor SF3b". Science. 300 (5621): 980–4. doi:10.1126/science.1084155. PMID12738865.
