Tyrosine phosphatase signalling in a lower plant: cell-cycle and oxidative stress-regulated expression of the Chlamydomonas eugametos VH-PTP13 gene

Plant J. 1995 Jun;7(6):981-8. doi: 10.1046/j.1365-313x.1995.07060981.x.


The first evidence for tyrosine phosphatase signalling pathways in plants is presented by characterizing a putative protein tyrosine phosphatase gene from the unicellular green alga Chlamydomonas eugametos. This cDNA, referred to as VH-PTP13, contains an open reading frame specifying a protein with a molecular weight of 30.3 kDa, that has significant homology with a distinct group of dual-specificity phosphatases. The highest homology is found with CL-100, a human stress-response gene that regulates MAPkinase activity. The purified VH-PTP13 protein expressed in E. coli had phosphatase activity and inactivated MAPkinases from alfalfa and tobacco. Nondividing C. eugametos gametes did not express the VH-PTP13 gene whereas synchronously dividing vegetative cells only expressed VH-PTP13 in the early G1-phase of the cycle, implying a function there. When vegetative cells were subjected to oxidative stress, expression of the VH-PTP13 gene was strongly induced, analogous to the human CL-100 gene. Its potential role in plant signalling pathways is discussed.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Cycle
  • Chlamydomonas / enzymology
  • Chlamydomonas / genetics*
  • Cloning, Molecular
  • DNA, Complementary
  • Dual Specificity Phosphatase 3
  • Escherichia coli
  • Gene Expression Regulation*
  • Medicago sativa / enzymology
  • Medicago sativa / genetics
  • Molecular Sequence Data
  • Oxidative Stress*
  • Phylogeny
  • Protein Kinase Inhibitors
  • Protein Tyrosine Phosphatases / genetics*
  • Protein Tyrosine Phosphatases / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Signal Transduction*
  • Tyrosine / metabolism*


  • DNA, Complementary
  • Protein Kinase Inhibitors
  • Recombinant Proteins
  • Tyrosine
  • DUSP3 protein, human
  • Dual Specificity Phosphatase 3
  • Protein Tyrosine Phosphatases

Associated data

  • GENBANK/X77938