Identification of both shared and distinct proteins in the major and minor spliceosomes.
In metazoans, two distinct spliceosomes catalyzing pre-messenger RNA splicing have been identified. Here, the human U11/U12 small nuclear ribonucleoprotein (snRNP), a subunit of the minor (U12-dependent) spliceosome, was isolated. Twenty U11/U12 proteins were identified, including subsets unique to the minor spliceosome or common to both spliceosomes. Common proteins include four U2 snRNP polypeptides that constitute the essential splicing factor SF3b. A 35-kilodalton U11-associated protein homologous to the U1 snRNP 70K protein was also identified. These data provide fundamental information about proteins of the minor spliceosome and shed light on its evolutionary relationship to the major spliceosome.
Will
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CL
Institut für Molekularbiologie und Tumorforschung, Philipps-Universität, 35037 Marburg, Germany.
Schneider
C
C
Reed
R
R
Lührmann
R
R
D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D019143:Evolution, Molecular; D006367:HeLa Cells; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012326:RNA Splicing; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000032:analysis* / Q000302:isolation & purification; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000032:analysis* / Q000302:isolation & purification; D017411:Ribonucleoproteins, Small Nuclear / Q000032:analysis* / Q000302:isolation & purification; D017381:Spliceosomes / Q000737:chemistry*
D017412:Ribonucleoprotein, U1 Small Nuclear; D017413:Ribonucleoprotein, U2 Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; C098762:U11 small nuclear ribonucleoprotein, human; C552126:U11-U12 small nuclear ribonucleoprotein