SART3 associates with a post-splicing complex

J Cell Sci. 2023 Jan 15;136(2):jcs260380. doi: 10.1242/jcs.260380. Epub 2023 Jan 23.

Abstract

SART3 is a multifunctional protein that acts in several steps of gene expression, including assembly and recycling of the spliceosomal U4/U6 small nuclear ribonucleoprotein particle (snRNP). In this work, we provide evidence that SART3 associates via its N-terminal HAT domain with the 12S U2 snRNP. Further analysis showed that SART3 associates with the post-splicing complex containing U2 and U5 snRNP components. In addition, we observed an interaction between SART3 and the RNA helicase DHX15, which disassembles post-splicing complexes. Based on our data, we propose a model that SART3 associates via its N-terminal HAT domain with the post-splicing complex, where it interacts with U6 snRNA to protect it and to initiate U6 snRNA recycling before a next round of splicing.

Keywords: Recycling; Splicing; U2 snRNP; U6 snRNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • RNA Splicing* / genetics
  • RNA, Small Nuclear / genetics
  • RNA, Small Nuclear / metabolism
  • Ribonucleoprotein, U2 Small Nuclear / genetics
  • Ribonucleoprotein, U2 Small Nuclear / metabolism
  • Ribonucleoprotein, U4-U6 Small Nuclear / genetics
  • Ribonucleoprotein, U4-U6 Small Nuclear / metabolism
  • Ribonucleoprotein, U5 Small Nuclear / genetics
  • Ribonucleoprotein, U5 Small Nuclear / metabolism
  • Ribonucleoproteins, Small Nuclear / genetics
  • Ribonucleoproteins, Small Nuclear / metabolism
  • Spliceosomes* / genetics
  • Spliceosomes* / metabolism

Substances

  • RNA, Small Nuclear
  • Ribonucleoprotein, U4-U6 Small Nuclear
  • Ribonucleoprotein, U5 Small Nuclear
  • Ribonucleoprotein, U2 Small Nuclear
  • Ribonucleoproteins, Small Nuclear