BP

GO:0000398

mRNA splicing, via spliceosome

The joining together of exons from one or more primary transcripts of messenger RNA (mRNA) and the excision of intron sequences, via a spliceosomal mechanism, so that mRNA consisting only of the joined exons is produced.

IBA|IC|TAS

BP

GO:0034504

protein localization to nucleus

A process in which a protein is transported to, or maintained in, a location within the nucleus.

IEA

BP

GO:1900087

positive regulation of G1/S transition of mitotic cell cycle

Any cell cycle regulatory process that promotes the commitment of a cell from G1 to S phase of the mitotic cell cycle.

IEA

CC

GO:0000974

Prp19 complex

A protein complex consisting of Prp19 and associated proteins that is involved in the transition from the precatalytic spliceosome to the activated form that catalyzes step 1 of splicing, and which remains associated with the spliceosome through the second catalytic step. It is widely conserved, found in both yeast and mammals, though the exact composition varies. In S. cerevisiae, it contains Prp19p, Ntc20p, Snt309p, Isy1p, Syf2p, Cwc2p, Prp46p, Clf1p, Cef1p, and Syf1p.

IBA

CC

GO:0005634

nucleus

A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.

IDA

CC

GO:0005654

nucleoplasm

That part of the nuclear content other than the chromosomes or the nucleolus.

IDA|TAS

CC

GO:0005662

DNA replication factor A complex

A conserved heterotrimeric complex that binds nonspecifically to single-stranded DNA and is required for multiple processes in eukaryotic DNA metabolism, including DNA replication, DNA repair, and recombination. In all eukaryotic organisms examined the complex is composed of subunits of approximately 70, 30, and 14 kDa.

IDA

CC

GO:0005730

nucleolus

A small, dense body one or more of which are present in the nucleus of eukaryotic cells. It is rich in RNA and protein, is not bounded by a limiting membrane, and is not seen during mitosis. Its prime function is the transcription of the nucleolar DNA into 45S ribosomal-precursor RNA, the processing of this RNA into 5.8S, 18S, and 28S components of ribosomal RNA, and the association of these components with 5S RNA and proteins synthesized outside the nucleolus. This association results in the formation of ribonucleoprotein precursors; these pass into the cytoplasm and mature into the 40S and 60S subunits of the ribosome.

IDA

CC

GO:0016607

nuclear speck

A discrete extra-nucleolar subnuclear domain, 20-50 in number, in which splicing factors are seen to be localized by immunofluorescence microscopy.

IEA

CC

GO:0031965

nuclear membrane

Either of the lipid bilayers that surround the nucleus and form the nuclear envelope; excludes the intermembrane space.

IDA

CC

GO:0071011

precatalytic spliceosome

A spliceosomal complex that is formed by the recruitment of a preassembled U5-containing tri-snRNP to the prespliceosome. Although all 5 snRNPs are present, the precatalytic spliceosome is catalytically inactive. The precatalytic spliceosome includes many proteins in addition to those found in the associated snRNPs.

IBA

CC

GO:0071013

catalytic step 2 spliceosome

A spliceosomal complex that contains three snRNPs, including U5, bound to a splicing intermediate in which the first catalytic cleavage of the 5' splice site has occurred. The precise subunit composition differs significantly from that of the catalytic step 1, or activated, spliceosome, and includes many proteins in addition to those found in the associated snRNPs.

IDA

CC

GO:0080008

Cul4-RING E3 ubiquitin ligase complex

A ubiquitin ligase complex in which a cullin from the Cul4 family and a RING domain protein form the catalytic core; substrate specificity is conferred by an adaptor protein.

IBA

MF

GO:0005515

protein binding

Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).

IPI