ESCRT components regulate the expression of the ER/Golgi calcium pump gene PMR1 through the Rim101/Nrg1 pathway in budding yeast

J Mol Cell Biol. 2013 Oct;5(5):336-44. doi: 10.1093/jmcb/mjt025. Epub 2013 Aug 9.

Abstract

The endosomal sorting complex required for transport (ESCRT) complexes function to form multivesicular bodies for sorting of proteins destined for the yeast vacuole or the mammalian lysosome. ESCRT components are well conserved in eukaryotes, and their mutations cause neurodegenerative diseases and other cellular pathologies in humans. PMR1 is the orthologous gene of two human genes for calcium pumps secretory pathway Ca(2+)-ATPase (SPCA1, ATP2C1) and sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA, ATP2A2), which are mutated in Hailey-Hailey and Darier genetic diseases, respectively. Here we show that deletion mutation of ESCRT components Snf7, Snf8, Stp22, Vps20, Vps25, Vps28, or Vps36 activates the calcium/calcineurin signaling in yeast cells, but surprisingly leads to a nearly 50% reduction in expression of the ER/Golgi calcium pump gene PMR1 independent of calcium stress. These ESCRT mutants are known to have a defect in Rim101 activation. Ectopic expression of a constitutively active form of Rim101 or further deletion of NRG1 in these mutants partially suppresses their calcium hypersensitivity. Deletion of NRG1 also completely rescues the expression of PMR1 in these mutants to the level of the wild type. Promoter mutagenesis, gel electrophoretic mobility shift assay, and chromatin immunoprecipitation analysis demonstrate that Nrg1 binds to two motifs in the PMR1 promoter. In addition, expression of PMR1 under the control of its promoters with mutated Nrg1-binding motifs suppresses the calcium hypersensitivity of these ESCRT mutants. Collectively, these data have uncovered a function of ESCRT components in regulating PMR1 expression through the Nrg1/Rim101 pathway. Our findings provide important clues for understanding human diseases related to calcium homeostasis.

Keywords: ESCRT; Nrg1; Pmr1; Rim101; calcineurin; calcium pump.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Calcineurin / metabolism
  • Calcium / metabolism
  • Calcium / pharmacology
  • Calcium-Transporting ATPases / genetics*
  • Calcium-Transporting ATPases / metabolism
  • Endoplasmic Reticulum / drug effects
  • Endoplasmic Reticulum / metabolism*
  • Endosomal Sorting Complexes Required for Transport / metabolism*
  • Gene Deletion
  • Gene Expression Regulation, Fungal* / drug effects
  • Golgi Apparatus / drug effects
  • Golgi Apparatus / metabolism*
  • Humans
  • Models, Biological
  • Molecular Chaperones
  • Mutation / genetics
  • Promoter Regions, Genetic / genetics
  • Protein Binding / drug effects
  • Protein Binding / genetics
  • Proteolysis / drug effects
  • Repressor Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Saccharomycetales / drug effects
  • Saccharomycetales / genetics*
  • Signal Transduction / drug effects
  • Signal Transduction / genetics

Substances

  • Endosomal Sorting Complexes Required for Transport
  • Molecular Chaperones
  • NRG1 protein, S cerevisiae
  • RIM101 protein, S cerevisiae
  • Repressor Proteins
  • SSC1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Calcineurin
  • Calcium-Transporting ATPases
  • Calcium