Biomaterial Database

The ATP requirement for U2 snRNP addition is linked to the pre-mRNA region 5' to the branch site. 2001

C M Newnham, and C C Query

Department of Cell Biology, Albert Einstein College of Medicine. New York, New York 10461-1975, USA.

Association of U2 snRNP with the pre-mRNA branch region is the first ATP-dependent step in spliceosome assembly. The basis of this energy dependence is not known. Previously, we identified minimal intron-derived substrates that form complexes with U2 independent of ATP. Here, we identify the intron region linked to the ATP dependence of this step by comparing these substrates to longer RNAs that recapitulate the ATP requirement. This region needed to impose ATP dependence lies immediately 5' to the branch site. Sequences ranging from 6 to 14 nt yield a near linear inhibitory effect on efficiency of complex formation with U2 snRNP, with 18 nt yielding near maximal ATP dependence. This region is not protected prior to U2 addition, and RNase H targeting of the region within nuclear extract converts an ATP-dependent substrate into an ATP-independent one. Within this region, there is no sequence specificity linked with the ATP requirement, as neither a specific sequence is needed, nor even nucleobases. These data and the results of other modifications suggest models in which the 18-nt region is a target for interactions with U2 snRNP in an ATP-bound or -activated conformation.

UI	MeSH Term	Description	Entries
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D012322	RNA Precursors	RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.	Precursor RNA,Primary RNA Transcript,RNA, Messenger, Precursors,RNA, Ribosomal, Precursors,RNA, Small Nuclear, Precursors,RNA, Transfer, Precursors,Pre-mRNA,Pre-rRNA,Pre-snRNA,Pre-tRNA,Primary Transcript, RNA,RNA Precursor,mRNA Precursor,rRNA Precursor,snRNA Precursor,tRNA Precursor,Pre mRNA,Pre rRNA,Pre snRNA,Pre tRNA,Precursor, RNA,Precursor, mRNA,Precursor, rRNA,Precursor, snRNA,Precursor, tRNA,Precursors, RNA,RNA Primary Transcript,RNA Transcript, Primary,RNA, Precursor,Transcript, Primary RNA,Transcript, RNA Primary
D012326	RNA Splicing	The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.	RNA, Messenger, Splicing,Splicing, RNA,RNA Splicings,Splicings, RNA
D017413	Ribonucleoprotein, U2 Small Nuclear	A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U2 snRNP along with other small nuclear ribonucleoproteins (U1, U4-U6, and U5) assemble into SPLICEOSOMES that remove introns from pre-mRNA by splicing. The U2 snRNA forms base pairs with conserved sequence motifs at the branch point, which associates with a heat- and RNAase-sensitive factor in an early step of splicing.	Small Nuclear Ribonucleoproteins, U2,U2 Small Nuclear Ribonucleoproteins,U2 snRNP,Ribonucleoproteins, Small, U2
D020121	5' Untranslated Regions	The sequence at the 5' end of the messenger RNA that does not code for product. This sequence contains the ribosome binding site and other transcription and translation regulating sequences.	5'UTR,Leader Sequences, mRNA,Leader mRNA Sequences,mRNA Leader Sequences,5' UTR,5' UTRs,5' Untranslated Region,5'UTRs,Leader Sequence, mRNA,Leader mRNA Sequence,Region, 5' Untranslated,Regions, 5' Untranslated,Sequence, Leader mRNA,Sequence, mRNA Leader,Sequences, Leader mRNA,Sequences, mRNA Leader,UTR, 5',UTRs, 5',Untranslated Region, 5',Untranslated Regions, 5',mRNA Leader Sequence,mRNA Sequence, Leader,mRNA Sequences, Leader
D022821	RNA Splice Sites	Nucleotide sequences located at the ends of EXONS and recognized in pre-messenger RNA by SPLICEOSOMES. They are joined during the RNA SPLICING reaction, forming the junctions between exons.	Splice Acceptor Site,Splice Donor Site,3' Splice Site,5' Splice Site,Alternative Splice Sites,Cryptic Splice Sites,3' Splice Sites,5' Splice Sites,Acceptor Site, Splice,Acceptor Sites, Splice,Alternative Splice Site,Cryptic Splice Site,Donor Site, Splice,Donor Sites, Splice,Splice Acceptor Sites,Splice Donor Sites,Splice Site, 3',Splice Site, 5',Splice Site, Alternative,Splice Site, Cryptic,Splice Sites, 3',Splice Sites, 5',Splice Sites, Alternative,Splice Sites, Cryptic