The intracellular distribution of the components of the GET system in vascular plants

Biochim Biophys Acta Mol Cell Res. 2019 Oct;1866(10):1650-1662. doi: 10.1016/j.bbamcr.2019.06.012. Epub 2019 Jun 21.

Abstract

The guided entry of tail-anchored proteins (GET) pathway facilitates targeting and insertion of tail-anchored proteins into membranes. In plants, such a protein insertion machinery for the endoplasmic reticulum as well as constituents within mitochondrial and chloroplasts were discovered. Previous phylogenetic analysis revealed that Get3 sequences of Embryophyta form two clades representing cytosolic ("a") and organellar ("bc") GET3 homologs, respectively. Cellular fractionation of Arabidopsis thaliana seedlings and usage of the self-assembly GFP system in protoplasts verified the cytosolic (ATGet3a), plastidic (ATGet3b) and mitochondrial (ATGet3c) localization of the different homologs. The identified plant homologs of Get1 and Get4 in A. thaliana are localized in ER and cytosol, respectively, implicating a degree of conservation of the GET pathway in A. thaliana. Transient expression of Get3 homologs of Solanum lycopersicum, Medicago × varia or Physcomitrella patens with the self-assembly GFP technique in homologous and heterologous systems verified that multiple Get3 homologs with differing subcellular localizations are common in plants. Chloroplast localized Get3 homologs were detected in all tested plant systems. In contrast, mitochondrial localized Get3 homologs were not identified in S. lycopersicum, or P. patens, while we confirmed on the example of A. thaliana proteins that mitochondrial localized Get3 proteins are properly targeted in S. lycopersicum as well.

Keywords: Chloroplasts; Get components; Mitochondria; Plants; Protein localization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases
  • Arabidopsis / metabolism
  • Bryopsida / metabolism
  • Chloroplasts
  • Cytoplasm / metabolism
  • Cytosol / metabolism*
  • Embryophyta
  • Endoplasmic Reticulum / metabolism
  • Green Fluorescent Proteins
  • Guanine Nucleotide Exchange Factors
  • Lycopersicon esculentum / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mitochondria / metabolism
  • Phylogeny
  • Plant Proteins / metabolism*
  • Plants / metabolism*
  • Protein Transport / physiology*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins
  • Seedlings

Substances

  • Guanine Nucleotide Exchange Factors
  • Membrane Proteins
  • Plant Proteins
  • Saccharomyces cerevisiae Proteins
  • Green Fluorescent Proteins
  • Adenosine Triphosphatases
  • Get3 protein, S cerevisiae