Histidine-containing phosphotransfer (HPt) signal transducers implicated in His-to-Asp phosphorelay in Arabidopsis

Plant Cell Physiol. 1998 Dec;39(12):1258-68. doi: 10.1093/oxfordjournals.pcp.a029329.

Abstract

His to Asp phosphorelay signal transduction mechanisms involve three types of widespread signaling components: a sensor His-kinase, a response regulator, and a histidine-containing phosphotransfer (HPt) domain. In Arabidopsis, several sensor His-kinases have recently been discovered (e.g., ETR1 and CKI1) through extensive genetic studies. Furthermore, a recent search for response regulators in this higher plant revealed that it possesses a group of response regulators (ARR-series), each of which exhibits the phospho-accepting receiver function. However, no signal transducer containing the HPt domain has been reported. Here we identify three distinct Arabidopsis genes (AHP1 to AHP3), each encoding a signal transducer containing a HPt domain. Both in vivo and in vitro evidence that each AHP can function as a phospho-transmitting HPt domain with an active histidine site was obtained by employing both the Escherichia coli and yeast His-Asp phosphorelay systems. It was demonstrated that AHP1 exhibits in vivo ability to complement a mutational lesion of the yeast YPD1 gene, encoding a typical HPt domain involved in an osmosensing signal transduction. It was also demonstrated that AHPs can interact in vitro with ARRs through the His-Asp phosphotransfer reaction. It was thus suggested that the uncovered sensors-AHPs-ARRs lineups may play important roles in propagating environmental stimuli through the multistep His-Asp phosphorelay in Arabidopsis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis Proteins*
  • Aspartic Acid / metabolism*
  • Catalytic Domain
  • Chromosome Mapping
  • DNA-Binding Proteins / genetics
  • Escherichia coli / genetics
  • Fungal Proteins / genetics
  • Genes, Plant*
  • Genetic Complementation Test
  • Histidine / metabolism*
  • Histidine Kinase
  • Intracellular Signaling Peptides and Proteins
  • Molecular Sequence Data
  • Phosphotransferases / genetics*
  • Plant Proteins / genetics
  • Protein Kinases / genetics
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Signal Transduction / genetics

Substances

  • AHP1 protein, Arabidopsis
  • AHP2 protein, Arabidopsis
  • AHP3 protein, Arabidopsis
  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • Fungal Proteins
  • Intracellular Signaling Peptides and Proteins
  • Plant Proteins
  • Saccharomyces cerevisiae Proteins
  • Aspartic Acid
  • Histidine
  • Phosphotransferases
  • Protein Kinases
  • YPD1 protein, S cerevisiae
  • Histidine Kinase