TY - JOUR
T1 - The splicing factor SF2/ASF binds to ARS homologs in a human rDNA replication origin
AU - He, Mai
AU - Shah, Dimal
AU - Choung, Hae Yoon Grace
AU - Coffman, Frederick D.
PY - 2009/8/15
Y1 - 2009/8/15
N2 - The function of the relatively well-studied DNA replication origins in the yeast Saccharomyces cerevisiae is dependent upon interactions between origin replication complex (ORC) proteins and several defined origin sequence elements, including the 11 bp ARS consensus sequence (ACS). Although the ORC proteins, as well as numerous other protein components required for DNA replication initiation, are largely conserved between yeast and mammals, DNA sequences within mammalian replication origins are highly variable and sequences homologous to the yeast ACS elements are generally not present. We have previously identified several replication initiation sites within the nontranscribed spacer region of the human ribosomal RNA gene, and found that two highly utilized sites each contain a homologue of the yeast ACS embedded within a DNA unwinding element and a matrix attachment region. Here we examine protein binding within these initiation sites, and demonstrate that these ACS homologues specifically bind the alternate splicing factor SF2/ ASF as well as GAPDH in vitro, and present evidence that the SF2/ASF interaction also occurs within the nuclei of intact cells. As the moderate upregulation of SF2/ASF has been linked to oncogenesis through the promotion of alternatively spliced forms of several regulatory proteins, our results suggest an additional mechanism by which SF2/ASF may influence the transformed cell phenotype.
AB - The function of the relatively well-studied DNA replication origins in the yeast Saccharomyces cerevisiae is dependent upon interactions between origin replication complex (ORC) proteins and several defined origin sequence elements, including the 11 bp ARS consensus sequence (ACS). Although the ORC proteins, as well as numerous other protein components required for DNA replication initiation, are largely conserved between yeast and mammals, DNA sequences within mammalian replication origins are highly variable and sequences homologous to the yeast ACS elements are generally not present. We have previously identified several replication initiation sites within the nontranscribed spacer region of the human ribosomal RNA gene, and found that two highly utilized sites each contain a homologue of the yeast ACS embedded within a DNA unwinding element and a matrix attachment region. Here we examine protein binding within these initiation sites, and demonstrate that these ACS homologues specifically bind the alternate splicing factor SF2/ ASF as well as GAPDH in vitro, and present evidence that the SF2/ASF interaction also occurs within the nuclei of intact cells. As the moderate upregulation of SF2/ASF has been linked to oncogenesis through the promotion of alternatively spliced forms of several regulatory proteins, our results suggest an additional mechanism by which SF2/ASF may influence the transformed cell phenotype.
KW - ARS sequence
KW - Alternate splicing factor
KW - DNA replication
KW - GAPDH
KW - Origin-binding protein
KW - Replication origin
KW - Ribosomal RNA gene
KW - SF2/ASF
UR - http://www.scopus.com/inward/record.url?scp=69249229774&partnerID=8YFLogxK
U2 - 10.4161/cc.8.16.9365
DO - 10.4161/cc.8.16.9365
M3 - Article
C2 - 19633418
AN - SCOPUS:69249229774
SN - 1538-4101
VL - 8
SP - 2631
EP - 2642
JO - Cell Cycle
JF - Cell Cycle
IS - 16
ER -