Large-Scale Proteomic Analysis of the Human Spliceosome

TLDR

A prior proteomic study identified 42 spliceosome-associated factors, including 19 novel proteins. Using advanced mass spectrometry, the study identified 311 spliceosome-associated proteins, including all known essential factors, 96 novel proteins—55 with splicing/RNA‑processing domains—and 20 transcription‑related proteins, offering the most comprehensive human spliceosome inventory to date.

Abstract

In a previous proteomic study of the human spliceosome, we identified 42 spliceosome-associated factors, including 19 novel ones. Using enhanced mass spectrometric tools and improved databases, we now report identification of 311 proteins that copurify with splicing complexes assembled on two separate pre-mRNAs. All known essential human splicing factors were found, and 96 novel proteins were identified, of which 55 contain domains directly linking them to functions in splicing/RNA processing. We also detected 20 proteins related to transcription, which indicates a direct connection between this process and splicing. This investigation provides the most detailed inventory of human spliceosome-associated factors to date, and the data indicate a number of interesting links coordinating splicing with other steps in the gene expression pathway.