U1-snRNP A
Homo sapiens
True
human, mass spectrometry, nuclear mRNA splicing via spliceosome, prespliceosome, snRNP, U1 snRNP
Interphase
splicing speckles
GO:0000398
nuclear mRNA splicing, via spliceosome
GO:0008248
pre-mRNA splicing factor activity
Mud1
Saccharomyces cerevisiae