title: Structure-function analysis of the U2 snRNP-associated splicing factor SF3a.
abstract: Human splicing factor SF3a is a part of the 17 S U2 snRNP (small nuclear ribonucleoprotein), which interacts with the pre-mRNA branch site early during spliceosome formation. The SF3a subunits of 60, 66 and 120 kDa are all required for SF3a function in vitro. Depletion of individual subunits from HeLa cells by RNA interference results in a global inhibition of splicing, indicating that SF3a is a constitutive splicing factor. Structure-function analyses have defined domains necessary for interactions within the SF3a heterotrimer, association with the U2 snRNP and spliceosome assembly. Studies aimed at the identification of regions in SF3a60 and SF3a66, required for proper intracellular localization, have led to a model for the final steps in U2 snRNP biogenesis and the proposal that SF3a is incorporated into the U2 snRNP in Cajal bodies.
authors.affiliation: Department of Cell Biology, University of Geneva, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland. angela.kraemer@cellbio.unige.ch
authors.forename: A
authors.initials: A
authors.lastname: Krämer
authors.forename: F
authors.initials: F
authors.lastname: Ferfoglia
authors.forename: C-J
authors.initials: CJ
authors.lastname: Huang
authors.forename: F
authors.initials: F
authors.lastname: Mulhaupt
authors.forename: D
authors.initials: D
authors.lastname: Nesic
authors.forename: G
authors.initials: G
authors.lastname: Tanackovic
mesh_terms: D000818:Animals; D006801:Humans; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D021122:Protein Subunits; D017413:Ribonucleoprotein, U2 Small Nuclear; C088049:splicing factor 3a