TY - JOUR
T1 - Specific sequence features, recognized by the SMN complex, identify snRNAs and determine their fate as snRNPs
AU - Golembe, Tracey J.
AU - Yong, Jeongsik
AU - Dreyfuss, Gideon
PY - 2005/12
Y1 - 2005/12
N2 - The survival of motor neurons (SMN) complex is essential for the biogenesis of spliceosomal small nuclear ribonucleoproteins (snRNPs) as it binds to and delivers Sm proteins for assembly of Sm cores on the abundant small nuclear RNAs (snRNAs). Using the conserved snRNAs encoded by the lymphotropic Herpesvirus saimiri (HVS), we determined the specific sequence and structural features of RNAs for binding to the SMN complex and for Sm core assembly. We show that the minimal SMN complex-binding domain in snRNAs, except U1, is comprised of an Sm site (AUUUUUG) and an adjacent 3′ stem-loop. The adenosine and the first and third uridines of the Sm site are particularly critical for binding of the SMN complex, which directly contacts the backbone phosphates of these uridines. The specific sequence of the adjacent stem (7 to 12 base pairs)-loop (4 to 17 nucleotides) is not important for SMN complex binding, but it must be located within a short distance of the 3′ end of the RNA for an Sm core to assemble. Importantly, these defining characteristics are discerned by the SMN complex and not by the Sm proteins, which can bind to and assemble on an Sm site sequence alone. These findings demonstrate that the SMN complex is the identifier, as well as assembler, of the abundant class of snRNAs in cells because it is able to recognize an snRNP code that they contain.
AB - The survival of motor neurons (SMN) complex is essential for the biogenesis of spliceosomal small nuclear ribonucleoproteins (snRNPs) as it binds to and delivers Sm proteins for assembly of Sm cores on the abundant small nuclear RNAs (snRNAs). Using the conserved snRNAs encoded by the lymphotropic Herpesvirus saimiri (HVS), we determined the specific sequence and structural features of RNAs for binding to the SMN complex and for Sm core assembly. We show that the minimal SMN complex-binding domain in snRNAs, except U1, is comprised of an Sm site (AUUUUUG) and an adjacent 3′ stem-loop. The adenosine and the first and third uridines of the Sm site are particularly critical for binding of the SMN complex, which directly contacts the backbone phosphates of these uridines. The specific sequence of the adjacent stem (7 to 12 base pairs)-loop (4 to 17 nucleotides) is not important for SMN complex binding, but it must be located within a short distance of the 3′ end of the RNA for an Sm core to assemble. Importantly, these defining characteristics are discerned by the SMN complex and not by the Sm proteins, which can bind to and assemble on an Sm site sequence alone. These findings demonstrate that the SMN complex is the identifier, as well as assembler, of the abundant class of snRNAs in cells because it is able to recognize an snRNP code that they contain.
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U2 - 10.1128/MCB.25.24.10989-11004.2005
DO - 10.1128/MCB.25.24.10989-11004.2005
M3 - Article
C2 - 16314521
AN - SCOPUS:28544439056
SN - 0270-7306
VL - 25
SP - 10989
EP - 11004
JO - Molecular and cellular biology
JF - Molecular and cellular biology
IS - 24
ER -