Targeting and membrane insertion into the endoplasmic reticulum membrane of Saccharomyces cerevisiae essential protein Rot1

FEMS Yeast Res. 2010 Sep;10(6):639-47. doi: 10.1111/j.1567-1364.2010.00653.x. Epub 2010 Jun 7.

Abstract

Rot1 is an essential yeast protein that has been related to cell wall biosynthesis, actin cytoskeleton dynamics and protein folding. Rot1 is an N-glycosylated protein anchored to the nuclear envelope-endoplasmic reticulum (ER) membrane by a transmembrane domain at its C-terminal end. Rot1 is translocated to the ER by a post-translational mechanism. Here, we investigate the protein domain required to target and translocate Rot1 to the ER membrane. We found that several deletions of the N-terminal region of Rot1 prevented neither membrane targeting nor the insertion of this protein. Interestingly, we obtained the same results when different truncated forms in the C-terminal transmembrane domain were analyzed, suggesting the presence of an internal topogenic element that is capable of translocating Rot1 to the ER. To identify this sequence, we generated a combination of N- and C-terminal deletion mutants of Rot1 and we investigated their insertion into the membrane. The results show that two regions, amino acids 26-60 and 200-228, are involved in the post-translational translocation of Rot1 across the ER membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Endoplasmic Reticulum / metabolism*
  • Intracellular Membranes / metabolism*
  • Membrane Proteins / metabolism*
  • Molecular Chaperones / metabolism*
  • Protein Structure, Tertiary
  • Protein Transport
  • Recombination, Genetic
  • Saccharomyces cerevisiae / cytology*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Sequence Deletion

Substances

  • Membrane Proteins
  • Molecular Chaperones
  • ROT1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins