Domain Requirements and Genetic Interactions of the Mud1 Subunit of the Saccharomyces cerevisiae U1 snRNP. Academic Article uri icon

Overview

abstract

  • Mud1 is an inessential 298-amino acid protein subunit of the Saccharomyces cerevisiae U1 snRNP. Mud1 consists of N-terminal and C-terminal RRM domains (RRM1 and RRM2) separated by a linker domain. Synthetic lethal interactions of mud1∆ with deletions of inessential spliceosome components Nam8, Mud2, and Msl1, or missense mutations in the branchpoint-binding protein Msl5 enabled us to dissect genetically the domain requirements for Mud1 function. We find that the biological activities of Mud1 can be complemented by co-expressing separately the RRM1 (aa 1-127) and linker-RRM2 (aa 128-298) modules. Whereas RRM1 and RRM2 (aa 197-298) per se are inactive in all tests of functional complementation, the linker-RRM2 by itself partially complements a subset of synthetic lethal mud1∆ interactions. Linker segment aa 155 to 196 contains a nuclear localization signal rich in basic amino acids that is necessary for RRM2 activity in mud1∆ complementation. Alanine scanning mutagenesis indicates that none of the individual RRM1 amino acid contacts to U1 snRNA in the cryo-EM model of the yeast U1 snRNP is necessary for mud1∆ complementation activity.

publication date

  • January 9, 2019

Research

keywords

  • Ribonucleoprotein, U1 Small Nuclear
  • Ribonucleoprotein, U2 Small Nuclear
  • Ribonucleoproteins, Small Nuclear
  • Saccharomyces cerevisiae Proteins

Identity

PubMed Central ID

  • PMC6325900

Scopus Document Identifier

  • 85059796346

Digital Object Identifier (DOI)

  • 10.1534/g3.118.200781

PubMed ID

  • 30413416

Additional Document Info

volume

  • 9

issue

  • 1