Molecular and physiological characterisation of a 14-3-3 protein from lily pollen grains regulating the activity of the plasma membrane H+ ATPase during pollen grain germination and tube growth

Planta. 2001 May;213(1):132-41. doi: 10.1007/s004250000483.

Abstract

A 14-3-3 protein has been cloned and sequenced from a cDNA library constructed from mRNAs of mature pollen grains of Lilium longiflorum Thunb. Monoclonal antibodies (MUP 5 or MUP 15) highly specific against 14-3-3 proteins recognised a 30-kDa protein in the cytoplasmic fraction of many various lily tissues (leaves, bulbs, stems, anther filaments, pollen grains, stigmas) and in other plants (Arabidopsis seedlings, barley recombinant 14-3-3). In addition, 14-3-3 proteins were detected in a microsomal fraction isolated from pollen grains and tubes, and the amount of membrane-bound 14-3-3 proteins as well as the amount of the plasma membrane (PM) H+ ATPase increased during germination of pollen grains and tube growth. No change was observed in the cytoplasmic fraction. A further increase in the amount of 14-3-3 proteins in the microsomal fraction was observed when pollen grains were incubated in germination medium containing 1 microM fusicoccin (FC) whereas the number of 14-3-3s in the cytoplasmic fraction decreased. Fusicoccin also protected membrane-bound 14-3-3 proteins from dissociation after washing with the chaotropic salt KI. Furthermore, FC stimulated the PM H+ ATPase activity, the germination frequency and the growth rate of pollen tubes, thus indicating that a modulation of the PM H+ ATPase activity by interaction with 14-3-3 proteins may regulate germination and tube growth of lily pollen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins
  • Amino Acid Sequence
  • Antibodies, Monoclonal
  • Cell Membrane / enzymology
  • Cytoplasm / metabolism
  • Glycosides / pharmacology
  • Humans
  • Liliaceae / enzymology
  • Liliaceae / physiology*
  • Microsomes / metabolism
  • Molecular Sequence Data
  • Plant Proteins / genetics
  • Plant Proteins / physiology*
  • Pollen / drug effects
  • Pollen / growth & development*
  • Potassium Iodide / pharmacology
  • Proton-Translocating ATPases / metabolism*
  • RNA, Messenger / analysis
  • RNA, Plant / analysis
  • Sequence Homology, Amino Acid
  • Tissue Distribution
  • Tyrosine 3-Monooxygenase / genetics
  • Tyrosine 3-Monooxygenase / physiology*

Substances

  • 14-3-3 Proteins
  • Antibodies, Monoclonal
  • Glycosides
  • Plant Proteins
  • RNA, Messenger
  • RNA, Plant
  • Potassium Iodide
  • fusicoccin
  • Tyrosine 3-Monooxygenase
  • Proton-Translocating ATPases