Role of SR protein modular domains in alternative splicing specificity in vivo.
The SR proteins constitute a family of nuclear phosphoproteins which are required for constitutive splicing and also influence alternative splicing regulation. They have a modular structure consisting of one or two RNA recognition motifs (RRMs) and a C-terminal domain, rich in arginine and serine residues. The functional role of the different domains of SR proteins in constitutive splicing activity has been extensively studied in vitro; however, their contribution to alternative splicing specificity in vivo has not been clearly established. We sought to address how the modular domains of SR proteins contribute to alternative splicing specificity. The activity of a series of chimeric proteins consisting of domain swaps between different SR proteins showed that splice site selection is determined by the nature of the RRMs and that RRM2 of SF2/ASF has a dominant role and can confer specificity to a heterologous protein. In contrast, the identity of the RS domain is not important, as the RS domains are functionally interchangeable. The contribution of the RRMs to alternative splicing specificity in vivo suggests that sequence-specific RNA binding by SR proteins is required for this activity.
van Der Houven Van Oordt
W
W
MRC Human Genetics Unit, Western General Hospital, Edinburgh EH4 2XU, UK and Molecular Immunology Group, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK.
Newton
K
K
Screaton
G R
GR
Cáceres
J F
JF
D017500:Adenovirus E1A Proteins / Q000235:genetics; D017398:Alternative Splicing; D020816:Amino Acid Motifs; D005353:Fibronectins / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000378:metabolism*; D000068103:Serine-Arginine Splicing Factors; D013379:Substrate Specificity; D014162:Transfection
D017500:Adenovirus E1A Proteins; D005353:Fibronectins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D000068103:Serine-Arginine Splicing Factors