A Golgi-localized hexose transporter is involved in heterotrimeric G protein-mediated early development in Arabidopsis

Mol Biol Cell. 2006 Oct;17(10):4257-69. doi: 10.1091/mbc.e06-01-0046. Epub 2006 Jul 19.

Abstract

Signal transduction involving heterotrimeric G proteins is universal among fungi, animals, and plants. In plants and fungi, the best understood function for the G protein complex is its modulation of cell proliferation and one of several important signals that are known to modulate the rate at which these cells proliferate is D-glucose. Arabidopsis thaliana seedlings lacking the beta subunit (AGB1) of the G protein complex have altered cell division in the hypocotyl and are D-glucose hypersensitive. With the aim to discover new elements in G protein signaling, we screened for gain-of-function suppressors of altered cell proliferation during early development in the agb1-2 mutant background. One agb1-2-dependent suppressor, designated sgb1-1(D) for suppressor of G protein beta1 (agb1-2), restored to wild type the altered cell division in the hypocotyl and sugar hypersensitivity of the agb1-2 mutant. Consistent with AGB1 localization, SGB1 is found at the highest steady-state level in tissues with active cell division, and this level increases in hypocotyls when grown on D-glucose and sucrose. SGB1 is shown here to be a Golgi-localized hexose transporter and acts genetically with AGB1 in early seedling development.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Arabidopsis Proteins / physiology
  • Biological Transport
  • Cell Division
  • Cell Proliferation
  • GTP-Binding Protein beta Subunits / antagonists & inhibitors
  • GTP-Binding Protein beta Subunits / genetics
  • GTP-Binding Protein beta Subunits / metabolism
  • GTP-Binding Protein beta Subunits / physiology
  • Gene Expression Regulation, Plant*
  • Glucose / metabolism
  • Golgi Apparatus / metabolism*
  • Heterotrimeric GTP-Binding Proteins / physiology*
  • Molecular Sequence Data
  • Monosaccharide Transport Proteins / genetics
  • Monosaccharide Transport Proteins / metabolism*
  • Monosaccharide Transport Proteins / physiology
  • Phylogeny
  • RNA, Plant / metabolism*
  • Signal Transduction

Substances

  • AGB1 protein, Arabidopsis
  • Arabidopsis Proteins
  • GTP-Binding Protein beta Subunits
  • Monosaccharide Transport Proteins
  • RNA, Plant
  • SGB1 protein, Arabidopsis
  • Heterotrimeric GTP-Binding Proteins
  • Glucose