The lysine-rich motif of intrinsically disordered stress protein CDeT11-24 from Craterostigma plantagineum is responsible for phosphatidic acid binding and protection of enzymes from damaging effects caused by desiccation

J Exp Bot. 2012 Aug;63(13):4919-29. doi: 10.1093/jxb/ers173. Epub 2012 Jul 12.

Abstract

The late embryogenesis abundant (LEA)-like protein CDeT11-24 is one of the major desiccation-related phosphoproteins of the resurrection plant Craterostigma plantagineum. In this study, it was shown that CDeT11-24 is mostly intrinsically disordered and protects two different enzymes, citrate synthase and lactate dehydrogenase, against damaging effects caused by desiccation. Lipid-binding assays revealed that CDeT11-24 is able to interact with phosphatidic acid, although electrostatic repulsion was expected due to the overall negative net charge of the protein under the tested physiological conditions. CDeT11-24 carries an N-terminal lysine-rich sequence, which is predicted to form an amphipathic α-helix. Analysis of the truncated CDeT11-24 protein identified this region to be responsible for both activities: enzyme protection and phosphatidic acid interaction. Possible functions of the CDeT11-24 protein are discussed in the context of desiccation tolerance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs*
  • Amino Acid Sequence
  • Citrate (si)-Synthase / metabolism
  • Craterostigma / chemistry*
  • Craterostigma / genetics
  • Craterostigma / metabolism
  • Desiccation
  • Enzyme Assays
  • L-Lactate Dehydrogenase / metabolism
  • Models, Biological
  • Mutagenesis, Site-Directed
  • Phosphatidic Acids / metabolism
  • Plant Leaves / chemistry
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Proteins / chemistry*
  • Plant Proteins / genetics
  • Plant Proteins / isolation & purification
  • Plant Proteins / metabolism*
  • Recombinant Proteins
  • Sequence Alignment
  • Signal Transduction
  • Water / physiology

Substances

  • Phosphatidic Acids
  • Plant Proteins
  • Recombinant Proteins
  • late embryogenesis abundant protein, plant
  • Water
  • L-Lactate Dehydrogenase
  • Citrate (si)-Synthase